Battle Familiar and Pact of the Chain

I'm struggling with how Battle Familiar interacts with the Imp familiar from Pact of the Chain.

Battle Familiar has this sentence in it: "For the duration, your familiar can attack in addition to taking other actions as normal, and your familiar’s game statistics are replaced by the Battle Familiar stat block, but it retains its creature type, alignment, Hit Points, Hit Point Dice, and any features granted by the Find Familiar spell.  Your familiar gains a number of Temporary Hit Points equal to the Hit Points of the battle familiar."

I can't determine if stat block just means the STR, DEX, CON, etc or if this also includes it's Traits and Actions.  It's confused because Battle Familiar does use the Imp's Hit Points which are a part of the stat block.  Clearly I would like the Imp to retain it's invisibility, magic resistance, and sting but I just can't tell if these are being replaced by the Battle Familiar stat block.

How are you guys playing this?

Quote from SirBarnick >>

I'm struggling with how Battle Familiar interacts with the Imp familiar from Pact of the Chain.

Battle Familiar has this sentence in it: "For the duration, your familiar can attack in addition to taking other actions as normal, and your familiar’s game statistics are replaced by the Battle Familiar stat block, but it retains its creature type, alignment, Hit Points, Hit Point Dice, and any features granted by the Find Familiar spell.  Your familiar gains a number of Temporary Hit Points equal to the Hit Points of the battle familiar."

I can't determine if stat block just means the STR, DEX, CON, etc or if this also includes it's Traits and Actions.  It's confused because Battle Familiar does use the Imp's Hit Points which are a part of the stat block.  Clearly I would like the Imp to retain it's invisibility, magic resistance, and sting but I just can't tell if these are being replaced by the Battle Familiar stat block.

How are you guys playing this?

 

 All it's traits, saves, etc... are replaced.  That includes invisibility, magic resistance, etc...  

You retain the find familiar spell features, plus your hp and HD.  You might also keep Investment of the Chain Master abilities, talk to the DM.  But anything inherent in the form itself is lost.

Quote from Squirrelloid >>

Quote from SirBarnick >>

I'm struggling with how Battle Familiar interacts with the Imp familiar from Pact of the Chain.

Battle Familiar has this sentence in it: "For the duration, your familiar can attack in addition to taking other actions as normal, and your familiar’s game statistics are replaced by the Battle Familiar stat block, but it retains its creature type, alignment, Hit Points, Hit Point Dice, and any features granted by the Find Familiar spell.  Your familiar gains a number of Temporary Hit Points equal to the Hit Points of the battle familiar."

I can't determine if stat block just means the STR, DEX, CON, etc or if this also includes it's Traits and Actions.  It's confused because Battle Familiar does use the Imp's Hit Points which are a part of the stat block.  Clearly I would like the Imp to retain it's invisibility, magic resistance, and sting but I just can't tell if these are being replaced by the Battle Familiar stat block.

How are you guys playing this?

 

 All it's traits, saves, etc... are replaced.  That includes invisibility, magic resistance, etc...  

You retain the find familiar spell features, plus your hp and HD.  You might also keep Investment of the Chain Master abilities, talk to the DM.  But anything inherent in the form itself is lost.

So if this is true then Battle Familiar is a horrible spell for a Warlock who has Pact of the Chain to take.  An Imp's only gain is temp hit points.  At level 3 the spell let's the familiar attack twice (it's own attack + the Warlock's Bonus Action).  But an Imp would lose a significant amount of damage and the first attack at advantage (assuming it was invisible).  It's damage goes from 3d6+3 per attack down to 1d8+5.  It seems strange that a level 2 spell would make the Warlock familiar worse.

I think this character is getting the delete treatment.

Quote from SirBarnick >>

Quote from Squirrelloid >>

Quote from SirBarnick >>

I'm struggling with how Battle Familiar interacts with the Imp familiar from Pact of the Chain.

Battle Familiar has this sentence in it: "For the duration, your familiar can attack in addition to taking other actions as normal, and your familiar’s game statistics are replaced by the Battle Familiar stat block, but it retains its creature type, alignment, Hit Points, Hit Point Dice, and any features granted by the Find Familiar spell.  Your familiar gains a number of Temporary Hit Points equal to the Hit Points of the battle familiar."

I can't determine if stat block just means the STR, DEX, CON, etc or if this also includes it's Traits and Actions.  It's confused because Battle Familiar does use the Imp's Hit Points which are a part of the stat block.  Clearly I would like the Imp to retain it's invisibility, magic resistance, and sting but I just can't tell if these are being replaced by the Battle Familiar stat block.

How are you guys playing this?

 

 All it's traits, saves, etc... are replaced.  That includes invisibility, magic resistance, etc...  

You retain the find familiar spell features, plus your hp and HD.  You might also keep Investment of the Chain Master abilities, talk to the DM.  But anything inherent in the form itself is lost.

 

So if this is true then Battle Familiar is a horrible spell for a Warlock who has Pact of the Chain to take.  An Imp's only gain is temp hit points.  At level 3 the spell let's the familiar attack twice (it's own attack + the Warlock's Bonus Action).  But an Imp would lose a significant amount of damage and the first attack at advantage (assuming it was invisible).  It's damage goes from 3d6+3 per attack down to 1d8+5.  It seems strange that a level 2 spell would make the Warlock familiar worse.

I think this character is getting the delete treatment.

Battle Familiar is a stupidly good spell, but Warlocks with Pact of the Chain get stupidly good familiars choices.  I don't think letting that stack would be the best plan...

Depends on your DM's interpretation of the Battle Familiar spell.  It says   "If you have a familiar from the Find Familiar spell when you cast this spell, you empower your existing familiar rather than conjuring a new one"... 

Since you (as a Warlock) use the Find Familiar spell to summon your Imp, Quasit, Pseudodragon, etc., you are empowering your currently active familiar.

The next part of the spell says   "For the duration, your familiar can attack in addition to taking other actions as normal,"...  meaning it does not require you to give up one of your attacks if your using Pact of the Chain or a bonus action if you're using Investment of the Chain Master.

After that, the spell says "and your familiar’s game statistics are replaced by the Battle Familiar stat block, " ....   So I would say that this means that the familiar's stats (ability scores and their relevant modifiers; spell save DC's; AC, movement speeds, etc.) are swapped out for the new ones.

However, the next part says "but it retains its creature type, alignment, Hit Points, Hit Point Dice, and any features granted by the Find Familiar spell."   I would say that the only part that needs to be looked at here is the 'and ANY features granted by the Find Familiar spell', like Telepathic Connection, Combat, Disappearance and Only One Familiar sections.  Since a warlock gains an enhanced form of Find Familiar using Pact of the Chain, it allows for the choice of more creature types and also allows the use of forgoing one of the warlock's attacks to grant the familiar to use its own attacks.  Unique traits that come with the chosen familiar - invisibility, granting a bonus to saving throws, magic resistance, shape shifting, etc.) are part of the chosen creature so I would consider those as features that would be retained.  Stripping a familiar of its inherent abilities seems wrong.

The spell further says "Your familiar gains a number of Temporary Hit Points equal to the Hit Points of the battle familiar.  Battle Familiar ends early if the familiar has no more Temporary Hit Points left, and these Temporary Hit Points vanish if any remain when Battle Familiar ends.  Your familiar reverts to its previous form when Battle Familiar ends."  This last part seems pretty simple.  Your familiar keeps their original hit points and Hit Dice and adds temporary hit points equal to the Battle Familiar form you choose.  An Imp has 21 hit points and 6d4 hit dice (which don't change) so taking the Brute option would add a base of 30 temp hit points plus 5 temp hit points for each level over 2 that you can cast.

Anywho, those are my thoughts on the issue.  If you see any flaws, please let me know.

Quote from Boremvor >>

Depends on your DM's interpretation of the Battle Familiar spell.  It says   "If you have a familiar from the Find Familiar spell when you cast this spell, you empower your existing familiar rather than conjuring a new one"... 

Since you (as a Warlock) use the Find Familiar spell to summon your Imp, Quasit, Pseudodragon, etc., you are empowering your currently active familiar.

The next part of the spell says   "For the duration, your familiar can attack in addition to taking other actions as normal,"...  meaning it does not require you to give up one of your attacks if your using Pact of the Chain or a bonus action if you're using Investment of the Chain Master.

After that, the spell says "and your familiar’s game statistics are replaced by the Battle Familiar stat block, " ....   So I would say that this means that the familiar's stats (ability scores and their relevant modifiers; spell save DC's; AC, movement speeds, etc.) are swapped out for the new ones.

However, the next part says "but it retains its creature type, alignment, Hit Points, Hit Point Dice, and any features granted by the Find Familiar spell."   I would say that the only part that needs to be looked at here is the 'and ANY features granted by the Find Familiar spell', like Telepathic Connection, Combat, Disappearance and Only One Familiar sections.  Since a warlock gains an enhanced form of Find Familiar using Pact of the Chain, it allows for the choice of more creature types and also allows the use of forgoing one of the warlock's attacks to grant the familiar to use its own attacks.  Unique traits that come with the chosen familiar - invisibility, granting a bonus to saving throws, magic resistance, shape shifting, etc.) are part of the chosen creature so I would consider those as features that would be retained.  Stripping a familiar of its inherent abilities seems wrong.

The spell further says "Your familiar gains a number of Temporary Hit Points equal to the Hit Points of the battle familiar.  Battle Familiar ends early if the familiar has no more Temporary Hit Points left, and these Temporary Hit Points vanish if any remain when Battle Familiar ends.  Your familiar reverts to its previous form when Battle Familiar ends."  This last part seems pretty simple.  Your familiar keeps their original hit points and Hit Dice and adds temporary hit points equal to the Battle Familiar form you choose.  An Imp has 21 hit points and 6d4 hit dice (which don't change) so taking the Brute option would add a base of 30 temp hit points plus 5 temp hit points for each level over 2 that you can cast.

Anywho, those are my thoughts on the issue.  If you see any flaws, please let me know.

 

This is pretty clearly wrong.  You replace your familiar's entire statblock.  If you had a bat familiar, it would lose blindsight and flight when you cast Battle Familiar for a Brute form.  It would only retain the following from its statblock: its 1hp, 1d4 hd, creature type (Fey, Celestial, or Fiend as per Find Familiar), and alignment.  It also retains any features granted by the Find Familiar spell: notably Telepathic Connection and the ability to dismiss it to a pocket dimension as a bonus action.

The Warlock's alternate familiar forms are not features granted by the find familiar spell.  They're alternate statblocks - which explicitly get replaced.  Things like Magic Resistance, Invisibility, Shape  Shifting are traits of those stat blocks, and are replaced along with the rest of their statblock by the new stat block. 

The only part of Pact of the Chain Master that is retained is the ability to use your attack action to cause the familiar to attack as its reaction.  (As that is an additional feature granted to the Warlock by the find familiar spell).

Now, Investment of the Chain Master provides what are additional features granted by the find familiar spell.  You should retain those abilities.  (ie, Aerial or Aquatic, Quick Attack (although this is useless, as the battle familiar can already attack with its action), Necrotic or Radiant Damage, Your Save DC (not that this matters with Battle Familiar forms), and Resistance)

The Familiar Friend's Origin Feat features still work.  The hp increase is obviously and explicitly retained.  And it's still your familiar for Helpful Friend.

Other Familiar feats still work.  It's still your familiar.

Think of this like the Polymorph spell.  If you polymorph yourself, you lose access to your species features because your statblock is replaced.

Quote from Squirrelloid >>

[...] Think of this like the Polymorph spell.  If you polymorph yourself, you lose access to your species features because your statblock is replaced.

 Probably, you meant species traits. Additionally, class features and traits are not retained either with Polymorph.

Quote from Tarod_ >>

Quote from Squirrelloid >>

[...] Think of this like the Polymorph spell.  If you polymorph yourself, you lose access to your species features because your statblock is replaced.

 Probably, you meant species traits. Additionally, class features and traits are not retained either with Polymorph.

 Indeed.

Fortunately, familiars don't have class features or traits, so the comparison isn't disrupted by that =)

Quote from SirBarnick >>

Quote from Squirrelloid >>

Quote from SirBarnick >>

I'm struggling with how Battle Familiar interacts with the Imp familiar from Pact of the Chain.

Battle Familiar has this sentence in it: "For the duration, your familiar can attack in addition to taking other actions as normal, and your familiar’s game statistics are replaced by the Battle Familiar stat block, but it retains its creature type, alignment, Hit Points, Hit Point Dice, and any features granted by the Find Familiar spell.  Your familiar gains a number of Temporary Hit Points equal to the Hit Points of the battle familiar."

I can't determine if stat block just means the STR, DEX, CON, etc or if this also includes it's Traits and Actions.  It's confused because Battle Familiar does use the Imp's Hit Points which are a part of the stat block.  Clearly I would like the Imp to retain it's invisibility, magic resistance, and sting but I just can't tell if these are being replaced by the Battle Familiar stat block.

How are you guys playing this?

 

 All it's traits, saves, etc... are replaced.  That includes invisibility, magic resistance, etc...  

You retain the find familiar spell features, plus your hp and HD.  You might also keep Investment of the Chain Master abilities, talk to the DM.  But anything inherent in the form itself is lost.

 

So if this is true then Battle Familiar is a horrible spell for a Warlock who has Pact of the Chain to take.  An Imp's only gain is temp hit points.  At level 3 the spell let's the familiar attack twice (it's own attack + the Warlock's Bonus Action).  But an Imp would lose a significant amount of damage and the first attack at advantage (assuming it was invisible).  It's damage goes from 3d6+3 per attack down to 1d8+5.  It seems strange that a level 2 spell would make the Warlock familiar worse.

I think this character is getting the delete treatment.

I struggled with this for a while and finally realized the best solution is to have the Imp cast Battle Familiar. I am going to do this via a Ring of Spell Storing (already planning to give one to the imp to offload concentration on Darkness and to give me a few extra rollover spell slots). The Imp can also attune to the Necklace of the Beastly Familiar (Giant Scorpion) and upgrade the battle familiar to a giant scorpion. Sadly the giant scorpion will not benefit from Investment of the Chain Master or Familiar Friend but the Imp still will and you can have both an invisible Imp (w/ extra HP due to familiar friend if you go that way) and a front-line combatant with 82 effective hp, 60' blindsight, 40' movement speed, 2x auto-grapple attacks, and a poisonous sting.

Technically, the imp can make itself invisible first, and then you can cast battle familiar on it.  Battle familiar never requires you to see your familiar, and changing forms shouldn't end an ongoing spell effect (so long as the imp maintains concentration).  Now you have an invisible battle familiar - until it attacks.

@Squirrelloid:    Yeah, I messed that up.  I had to go back and re-read the definition of 'stat block' in the PHB where the entire stat block would be replaced.  Good catch on your part.

There's something important about Pact of the Chain features that gets left out of these discussions, the fact that it takes only a Magic action to recast Find Familiar, and doesn't cost a spell slot. 

Casting Find Familiar if you have Familiar Friend increases both the max hp and Current hp, so Pact of the Chain gives you a mini healing spell for your familair that way, but it also lets you change their form.

Since effects like polymorph do not 'stack', you only get one stat block, there's a pretty solid argument that the later transformation from recasting Find Familiar with Pact of the Chain would put the familiar into the Imp form, but with the bonus temp HP and the ability to attack independently of Battle Familiar, since those are part of the spell itself not the Stat block. 

You wouldn't get any of the other power that Battle Familiar grants, the better AC or multiattack, but if you Really want the imp's attack option, resistances, and invisibility action then it might be worth doing. 

You just have to keep a bunch of incense sticks around like doggy treats for your familir. (Save money and make your incense at home with an herbalism or alchemy kit!)

Quote from TeiranDragon >>

There's something important about Pact of the Chain features that gets left out of these discussions, the fact that it takes only a Magic action to recast Find Familiar, and doesn't cost a spell slot. 

Casting Find Familiar if you have Familiar Friend increases both the max hp and Current hp, so Pact of the Chain gives you a mini healing spell for your familair that way, but it also lets you change their form.

Since effects like polymorph do not 'stack', you only get one stat block, there's a pretty solid argument that the later transformation from recasting Find Familiar with Pact of the Chain would put the familiar into the Imp form, but with the bonus temp HP and the ability to attack independently of Battle Familiar, since those are part of the spell itself not the Stat block. 

You wouldn't get any of the other power that Battle Familiar grants, the better AC or multiattack, but if you Really want the imp's attack option, resistances, and invisibility action then it might be worth doing. 

You just have to keep a bunch of incense sticks around like doggy treats for your familir. (Save money and make your incense at home with an herbalism or alchemy kit!)

 
This is interesting - so you are going by this language from Find Familiar: "One Familiar Only. You can't have more than one familiar at a time. If you cast this spell while you have a familiar, you instead cause it to adopt a new eligible form." - So basically casting Find Familiar (no Spell Slot required for Warlock) when you already have a familiar, does not eliminate the old familiar it just changes it's form.

I am not sure about this language from Battle Familiar - it seems like your new familiar might automatically take on the Battle Familiar form again: "For the duration, your familiar can attack in addition to taking other actions as normal, and your familiar's game statistics are replaced by the Battle Familiar stat block, but it retains its creature type, alignment, Hit Points, Hit Point Dice, and any features granted by the Find Familiar spell."

Quote from StonyMac > 

[...] This is interesting - so you are going by this language from Find Familiar: "One Familiar Only. You can't have more than one familiar at a time. If you cast this spell while you have a familiar, you instead cause it to adopt a new eligible form." - So basically casting Find Familiar (no Spell Slot required for Warlock) when you already have a familiar, does not eliminate the old familiar it just changes it's form. [...]

 Not sure if it's the same, but my ruling is more aligned with this answer from Natrel (Pact of the Chain Familiar HPs and daily actions recovery after disappearance):

Quote from Natrel >>

It doesn't, because when it dies and you recall it, you get the same familiar that disappeared. If you want to regain these abilities without waiting, you need a new familiar entirely. For that, you need to use a Magic action to dismiss it forever, then call another one. As for how the HP behaves when changing form, there's no rule that I know of on this, so it's up to the DM. I'd say doing so restores all HP, if at least for simplicity.

Yah, that language in Battle Familiar is why I brought up Polymorph. It has a similar text line, like Battle Familiar, saying "shape-shift into Beast form for the duration."

When you're Polymorphed, anything which replaced your stat block again overrides the stat block Polymorph gave you. The only reason Druids don't just wild shape out of the spell is that they lose that capability when they lose their class abilities. But if somebody else hits you with a second. Polymorph spell, you'd take on the newer form. 

Battle Familiar's description doesn't say it would retrigger the stat block replacement, and I don't think anyone would argue that an adversary casting polymorph on your Battle Familiar to turn them into a fly would have the spell fail because Battle Familiar would reapply the Battle Familiar stat block. 

The rules for combining spell effects say that when the spells are different, they add their effects together. When they're the same spell, the stronger one overrides the weaker. (An upcast Armor of Agathys would replace a baseline version, not add the damage amounts together.) 

Battle Familiar, Find Familiar, Polymorph, they're all different spells, so they add together. Which stat block takes priority? The timing has to be what matters. The stat block replacement which happens last is the one that stays in effect, at least until that spell's duration ends. 

Animal Shapes is an example of a spell which grants a repeatable stat block replacement effect via a Magic Action, like Pact of the Chain can.

If you had Animal Shapes cast on you, then got hit with a Polymorph, you'd change into the polymorph form. 

But the Animal Shapes spell didn't end when Polymorph was cast. So the Animal Shapes caster can use a magic action to trigger a new stat block replacement.

Well this figures. I just made a post debating on whether or not going straight to third level for Battle Familiar was worth it for my Warlock as opposed to starting off Fighter. It sounds like as long as I have Pact of the Chain I’m doing better damage than I would with Battle Familiar. 

The effectiveness of Battle Familiar for a Pact of the Chain warlock will ebb and flow from level to level. Assuming you tend to summon an Imp, take Investment of the Chain at 5, summon the Battle Familiar in Brute form (or Flyer before your Brute can fly), and follow pretty normal improvements to your casting stat over levels, here is a summary of the rough effectiveness of the familiar at various Warlock levels either with (B) or without (~) the boost of Battle Familiar:

*sections placed in square brackets [like so] are going to be debatable with your DM based on if they will allow your familiar to use multiattack in its non-main action, or if they believe a familiar can take the Attack action of its own accord and then also take it when commanded using a Bonus Action (or if it can only take one Action) - personally I would allow it to use multiattack when it takes the Attack Action using its Reaction when you exchange one of your attacks to command it, but would not allow you to use a Bonus Action to make it Attack again after it has used its own Action and Reaction. 

1. AC13, 21HP fly, A: +5 3d6+3(p)
2. AC13, 21HP fly, A: +5 3d6+3(p)
3~. AC13, 21HP fly, A: +5 3d6+3(p)
3B. AC13, 51HP (or 41HP fly), +5 1d8+5(f), A: +5 1d8+5(f) --spell lvl 2
4~. AC13, 21HP fly, A: +5 3d6+3(p)
4B. AC13, 51HP (or 41HP fly), +6 1d8+5(f), A: +6 1d8+5(f) --spell lvl 2
(if you take Pact of the Blade and Thirsting Blade, the full Action here could be replaced by one attack of your own Attack Action)
5~. AC13, 21HP fly, A: +5 3d6+3(p/nr), BA: +5 3d6+3(p/nr)
5B. AC14, 56HP fly, +7 1d8+6(f), A: +7 1d8+6(f), [BA: +7 1d8+6(f)] --spell lvl 3
6~. AC13, 21HP fly, A: +5 3d6+3(p/nr), BA: +5 3d6+3(p/nr)
6B. AC14, 56HP fly, +7 1d8+6(f), A: +7 1d8+6(f), [BA: +7 1d8+6(f)] --spell lvl 3
7~. AC13, 21HP fly, A: +5 3d6+3(p/nr), BA: +5 3d6+3(p/nr)
7B. AC15, 61HP fly, 2x +7 1d8+7(f), A: [2x] +7 1d8+7(f), [BA: [2x] +7 1d8+7(f)] --spell lvl 4
8~. AC13, 21HP fly, A: +5 3d6+3(p/nr), BA: +5 3d6+3(p/nr)
8B. AC15, 61HP fly, 2x +8 1d8+7(f), A: [2x] +8 1d8+7(f), [BA: [2x] +8 1d8+7(f)] --spell lvl 4
9~. AC13, 21HP fly, A: +5 3d6+3(p/nr), BA: +5 3d6+3(p/nr)
9B. AC16, 66HP fly, 2x +9 1d8+8(f), A: [2x] +9 1d8+8(f), [BA: [2x] +9 1d8+8(f)] --spell lvl 5
...
13~. AC13, 21HP fly, A: +5 3d6+3(p/nr), BA: +5 3d6+3(p/nr)
13B. AC16, 66HP fly, 2x +10 1d8+8(f), A: [2x] +10 1d8+8(f), [BA: [2x] +10 1d8+8(f)] --spell lvl 5
...
17~. AC13, 21HP fly, A: +5 3d6+3(p/nr), BA: +5 3d6+3(p/nr)
17B. AC16, 66HP fly, 2x +12 1d8+8(f), A: [2x] +12 1d8+8(f), [BA: [2x] +12 1d8+8(f)] --spell lvl 5

A: = Warlock's Action, BA: = Warlock's Bonus Action, p/n/r/f = poison(mostly)/necrotic/radiant/force

So, we can see some benefits are always present - a Battle Familiar can always take the Attack action without any action cost to the Warlock, while a non-boosted familiar always requires the Warlocks full action, one Attack (if they have more than one) and/or a Bonus Action to make any attack at all. The Battle Familiar will soon be able to attack 3 times (or more DM-permitting) compared to the unboosted familar's once with the same action investment. A Battle Familiar is always hitting with Force (almost never resisted) vs the Imps majority damage of poison (very often resisted/immune). 

Other things we see improve over time are AC and HP of the boosted familiar - with the knowledge that even when it looses its temporary HP it will return to the original form and continue to have those original powers. Damage and Attack modifier increase significantly with spell and Warlock level.

At Warlock Level 3 there is not a great advantage to the spell beyond the extra HP. At Level 5 we start to see casting Battle Familiar having roughly equal value on the turn of casting, and delivering noticeable additional value on subsequent turns. But particularly when you hit Warlock Level 7, using your action to cast Battle Familiar and then allowing your Familiar to take the Attack Action (2 attacks, +7 to hit, 1d8+7 force) for free that turn (and every turn after that) will be very much more powerful than using the same Action to command an Imp to use its Sting attack (1 attack, +5 to hit, 1d6+3 piercing + 2d6 poison). Having a tough ally making two accurate, reasonably powerful attacks for free every turn is a great benefit over a familiar which can do nothing at all without using either your Action or Bonus Action (and Warlocks tend to have more options for a Bonus Action than say a Wizard might).

Familiar Friend origin feat, as well as the other Familiar feats and most of the other Chain Pact/Investment invocation bonuses tend to apply equally to a regular Chain or Battle Familiar, so I've not included them here.

Overall, a Chain Warlock doesn't need to always cast Battle Familiar, and it won't always increase their familiar's damage output (but will always improve their familiar's survivability) - but I think it is definitely an added option for them to widen their familiar options. Personally I am currently developing a Vestige Chain Warlock idea with a Skeleton Familiar (sometimes Battle), Undead Vestige Companion -- old dead god with immortal skeleton protector vibes. The new feats and the Battle Familiar spell really help flesh that idea out.

“Flesh” the idea out? But I thought he was a skeleton!

waka waka

All jokes aside, I appreciate the work put into this. I’m still trying to understand it all, but what I took away from it was that it’s still worth taking, which is reassuring to me. 

So this all assumes that you use the Familiars statblock attacks, not give them a magic item that lets them be useful without making attacks.

I feel like most optimized builds would try to craft and give magic items to familiars (POC ones also) that lets them do something productive (like Wand of Magic Missiles or Coiling Grasp Tattoo or something).

Quote from Actionsparda >>

Well this figures. I just made a post debating on whether or not going straight to third level for Battle Familiar was worth it for my Warlock as opposed to starting off Fighter. It sounds like as long as I have Pact of the Chain I’m doing better damage than I would with Battle Familiar. 

I mean, it depends heavily on what type of warlock you are as well. A duel wielding, heavy armor wearing Pact of the Blade lock who can give up their weakest attack every turn for a bonus hit from Battle Familiar is very different than a Blaster back line guy who wants the familair to use their reaction to boost their AC via Warlike Familiar. 

But there's a lot of synergy from the new Familiar feats that gives options for turning  the Pact of the Chain familiars into a proper menace.