I like the flavor of the pact of the blade and the undying patron, but I just cant see why a bladelock would pick anything other than hexblade. Some help with a build would be much appreciated
The Blade Pact will work with any Patron; just because it works best with the Hexblade is no reason not to pick the Patron you want. Now with that out of the way...
The Undying Patron doesn't give you much to work with; the Patron Features are mostly situational and they won't be useful very often. (Although in an undead-heavy adventure like Curse of Strahd, some of them become more useful.)
There are a few bright spots on the expanded spell list, but only a few. False Life scales up nicely; it'll eventually give you 1d4+24 thp once you've got 5th level pact magic slots. I recommend picking it up early if you decide to go melee.
However, I'd actually recommend picking up Xanathar's Guide and doing a ranged build. This works best for Half-elves or drow. But any race with a decent Dex or Cha bonus is fine.
If you're doing point buy, put your points in DEX and CHA. You'll need CON as well if possible.
At second level, get Agonizing Blast and Armor of Shadows invocations. (You already took the Eldritch Blast cantrip at first level.) You should also have the Hex spell.
At third level, you get Pact of the Blade. Swap out Agonizing Blast for the Improved Pact Weapon invocation. Now you can get a +1 Longbow for your pact weapon, and should have the Dex to use it. This does damage equivalent to Agonizing Blast.
One of your 2nd level spell picks at 3rd level should be Blindness/Deafness. This takes no concentration, so you can combo it with Hex. Blinding a foe gives you advantage and gives them disadvantage to attack you. This is kind of like the Devil's Sight/Darkness combo favored by other warlocks, except it doesn't interfere with your allies' vision. And it scales up; it'll eventually effect up to four targets at once when cast with a 5th level spell slot.
At 4th level, Elven Accuracy is the feat you want; this allows you to roll an extra die when attacking with advantage.
The rest is pretty standard Blade Pact stuff: Thirsting Blade at 5th level, Lifedrinker at 12th, etc.
Eldritch Blast gets 3 attacks at 11th level to your pact weapon's 2 attacks, so I'd recommend the Sharpshooter feat no later than 12th level so it can keep up.
This seems pretty cool, but is there anyway to get it to work in melee?
Up to a point, yes. You can always make your pact weapon a rapier instead of a longbow, anytime you wish to enter melee. Aside from the Sharpshooter feat, the build is identical. You'll want to choose a different feat or a stat boost at 12th level if you wish to focus on melee. Maxing out both Dex and Cha is a good idea because you'll be using Dex in melee, casting spells with Cha, and both stats will boost your weapon damage once you've got the Lifedrinker invocation. Also, at 12th level you'll have 3 spell slots, so you can use the Eldritch smite invocation without burning through all your slots. You can cast Hold Monster, then smite for automatic critical hits, which will double your weapon, and smite damage dice. That's 14d8+1+Dex+Cha. And you'll still have a spell slot left.
Something else you can do is crit fishing. Your pact weapon is a spell focus so you've got a hand free... use it. Fight with an off hand weapon, even if it's just a dagger. On any round when you can spare your bonus action, take an off-hand attack. Three attacks means three chances to crit. If you can get advantage, (which you can; you've got the Blindness spell!) the Elven Accuracy feat makes the odds of getting a crit quite good with three attacks. If you get a crit, then decide if it's a good time to use Eldritch Smite.
It's really all about making the most of Eldritch Smite; aside from that, from level 11 onward your Eldritch Blast technically outperforms your pact weapon, depending on your relative Dex and Cha scores. Maddening Hex and Relentless Hex might also be useful; they'll enhance the use of your Hex spell, whether you're fighting at range or in melee.
I'm tinkering with a build similar to this one in my current campaign (Archfey Patron, Blade Pact) and it's working alright so far. My spell list is different due to my patron, but the rest is pretty much the same. Hope this is helpful to you.
The undying bladelock build that I created was mostly for flavor. Hes a Tortle (AC17) who was almost killed by drowning and got lucky by meeting his patron. The way I built this guy was high strength and constitution. Pact of the blade and used a maul. Thirsting blade (2 attacks), improved pact weapon (+1), eldritch smite (force damage). He doesnt use spells often unless he needs to and is always at the front of combat. No need for high dex and his charisma is really low. Basically a barbarian with magic powers and magic weapons who lives forever.
I like the flavor of the pact of the blade and the undying patron, but I just cant see why a bladelock would pick anything other than hexblade. Some help with a build would be much appreciated
The Blade Pact will work with any Patron; just because it works best with the Hexblade is no reason not to pick the Patron you want. Now with that out of the way...
The Undying Patron doesn't give you much to work with; the Patron Features are mostly situational and they won't be useful very often. (Although in an undead-heavy adventure like Curse of Strahd, some of them become more useful.)
There are a few bright spots on the expanded spell list, but only a few. False Life scales up nicely; it'll eventually give you 1d4+24 thp once you've got 5th level pact magic slots. I recommend picking it up early if you decide to go melee.
However, I'd actually recommend picking up Xanathar's Guide and doing a ranged build. This works best for Half-elves or drow. But any race with a decent Dex or Cha bonus is fine.
If you're doing point buy, put your points in DEX and CHA. You'll need CON as well if possible.
At second level, get Agonizing Blast and Armor of Shadows invocations. (You already took the Eldritch Blast cantrip at first level.) You should also have the Hex spell.
At third level, you get Pact of the Blade. Swap out Agonizing Blast for the Improved Pact Weapon invocation. Now you can get a +1 Longbow for your pact weapon, and should have the Dex to use it. This does damage equivalent to Agonizing Blast.
One of your 2nd level spell picks at 3rd level should be Blindness/Deafness. This takes no concentration, so you can combo it with Hex. Blinding a foe gives you advantage and gives them disadvantage to attack you. This is kind of like the Devil's Sight/Darkness combo favored by other warlocks, except it doesn't interfere with your allies' vision. And it scales up; it'll eventually effect up to four targets at once when cast with a 5th level spell slot.
At 4th level, Elven Accuracy is the feat you want; this allows you to roll an extra die when attacking with advantage.
The rest is pretty standard Blade Pact stuff: Thirsting Blade at 5th level, Lifedrinker at 12th, etc.
Eldritch Blast gets 3 attacks at 11th level to your pact weapon's 2 attacks, so I'd recommend the Sharpshooter feat no later than 12th level so it can keep up.
DICE FALL, EVERYONE ROCKS!
This seems pretty cool, but is there anyway to get it to work in melee?
Up to a point, yes. You can always make your pact weapon a rapier instead of a longbow, anytime you wish to enter melee. Aside from the Sharpshooter feat, the build is identical. You'll want to choose a different feat or a stat boost at 12th level if you wish to focus on melee. Maxing out both Dex and Cha is a good idea because you'll be using Dex in melee, casting spells with Cha, and both stats will boost your weapon damage once you've got the Lifedrinker invocation. Also, at 12th level you'll have 3 spell slots, so you can use the Eldritch smite invocation without burning through all your slots. You can cast Hold Monster, then smite for automatic critical hits, which will double your weapon, and smite damage dice. That's 14d8+1+Dex+Cha. And you'll still have a spell slot left.
Something else you can do is crit fishing. Your pact weapon is a spell focus so you've got a hand free... use it. Fight with an off hand weapon, even if it's just a dagger. On any round when you can spare your bonus action, take an off-hand attack. Three attacks means three chances to crit. If you can get advantage, (which you can; you've got the Blindness spell!) the Elven Accuracy feat makes the odds of getting a crit quite good with three attacks. If you get a crit, then decide if it's a good time to use Eldritch Smite.
It's really all about making the most of Eldritch Smite; aside from that, from level 11 onward your Eldritch Blast technically outperforms your pact weapon, depending on your relative Dex and Cha scores. Maddening Hex and Relentless Hex might also be useful; they'll enhance the use of your Hex spell, whether you're fighting at range or in melee.
I'm tinkering with a build similar to this one in my current campaign (Archfey Patron, Blade Pact) and it's working alright so far. My spell list is different due to my patron, but the rest is pretty much the same. Hope this is helpful to you.
DICE FALL, EVERYONE ROCKS!
Thanks
if PHB+1 rule is in play, the reason you NEVER pick Hexblade for a Blade Pact warlock is: SCAG cantrips. LOL
The undying bladelock build that I created was mostly for flavor. Hes a Tortle (AC17) who was almost killed by drowning and got lucky by meeting his patron. The way I built this guy was high strength and constitution. Pact of the blade and used a maul. Thirsting blade (2 attacks), improved pact weapon (+1), eldritch smite (force damage). He doesnt use spells often unless he needs to and is always at the front of combat. No need for high dex and his charisma is really low. Basically a barbarian with magic powers and magic weapons who lives forever.