I'm coming from 3.5 and Pathfinder, and I have an idea for a character I'd like to try when I join a 5th edition group. I'm liking the idea of a blackguard/antipaladin style character who travels with a devil. My first thought was a warlock with a fiend patron but I'm not sure if there are features in the full class that would give me the features I want.

I know I can get an imp or quasit familiar through spellcasting classes, but that's not what I'm looking for for this character. I don't want to buy the books just to find out I can't make the character I want so I was wondering if there's something like this in the full edition.

Well, you could make an Oathbreaker Paladin for the class (Oathbreaker does require the subclass from the DMG, you can buy the book outright, or just the subclass for $1.99). Aside from asking your DM to allow an Imp as a pet/familiar/etc. otherwise I think you'd need to multiclass with Wizard for the Find Familiar spell. Note, these are the creatures listed for the Find Familiar spell: You gain the service of a familiar, a spirit that takes an animal form you choose: bat, cat, crab, frog (toad), hawk, lizard, octopus, owl, poisonous snake, fish (quipper), rat, raven, sea horse, spider, or weasel so you would still need to work out with your DM having any type of imp/devil companion.

Hope this helps.

Hello there,

A fiend patron warlock is also a good option for the character type you are describing. Details for the fiend patron warlock are available in the basic rules https://www.dndbeyond.com/sources/basic-rules/classes#Warlock Pact of the Chain feature also gives you access to extra familiar options, and the Paladin has access to the Find Steed spell https://www.dndbeyond.com/sources/basic-rules/spells#FindSteed (you decide if your steed is a celestial, fey or fiend).

Thanks BigHeartedGuy, I was hoping there was a class like corrupted paladin or something similar. What I was hoping for was, I start off in communication with a Devil Erinyes. Once my character levels up enough(so it wouldn't be OP) she would join the party as a guide/ally, if I follow instructions and keep to my patron's orders. I would sometimes get quests from my patron through her, whilest other times, maybe she would go off and do her own thing under disguise cause she is a Devil. It'd be a little bit familiar/cohort, gaining class levels if she sticks around long enough.

You might also want to look into Matt Coville's Illrigger class, kind of an anti-palladin. However, in 5e there's no alignment prerequisite for classes, so your take on an evil palladin who trucks with devils could just be...a palladin. The Oath of Vengeance or Oath of Conquest might me worth a look. 

Or of you want to kind of do it yourself you could go Eldritch Knight (fighter) and flavor your magic with infernal flair, or you could multi class fighter/warlock. If you only want spellcasting for the familiar then you could always take the Magic Initiate feat and choose Find Familiar as the spell you get, and you get some cantrips as a bonus. 

I'd advise against the Illrigger if you're new to 5e and returning to D&D. It's not a finished class, it's very much in flux and he's refining it/alpha testing it during his current campaign.

Honestly, Oathbreaker or Oath of Conquest is the easiest option for an evil paladin/anti-paladin

I would agree on Oathbreaker or Conquest paladin. You could either be variant human or spend your ASI at 4th to get Magic Initiate (Wizard) for Find Familiar, or with DM permission, wait until 5th level when you get Find Steed and have it be an imp or similar instead.

I also came from 3.5e into 5e without even knowing that 4e had happened. Of note, as some people mentioned, paladins no longer have an alignment requirement. Their requirement is to uphold their Oath and might not even be tied to a god.

Different paladins focus on various aspects of the cause of righteousness, but all are bound by the oaths that grant them power to do their sacred work. Although many paladins are devoted to gods of good, a paladin’s power comes as much from a commitment to justice itself as it does from a god.

*          *          *

The most important aspect of a paladin character is the nature of his or her holy quest.

*          *          *

Consider how your alignment colors the way you pursue your holy quest and the manner in which you conduct yourself before gods and mortals. Your oath and alignment might be in harmony, or your oath might represent standards of behavior that you have not yet attained.

*          *          *

When you reach 3rd level, you swear the oath that binds you as a paladin forever. Up to this time you have been in a preparatory stage, committed to the path but not yet sworn to it. Now you choose the Oath of Devotion, the Oath of the Ancients, or the Oath of Vengeance, all detailed at the end of the class description.

PHB - Ch 3: Classes - Paladin

There is also a section that goes over breaking your oath which can involve taking on the Oathbreaker paladin option from the Dungeon Master's Guide (DMG)

The oath that would bend to evil easiest would be the Oath of Vengeance.

If you go into the DMG then there is the Oathbreaker option. The Oathbreaker is fully evil though as that is a prerequisite to be an Oathbreaker.

A paladin must be evil and at least 3rd level to become an Oathbreaker. The paladin replaces the features specific to his or her Sacred Oath with Oathbreaker features.

DMG - Ch 4: Creating Nonplayer Characters - Paladin: Oathbreaker

Oathbreaker also has a section that goes over atonement for an oathbreaker to give you more options.

There are also a few other Oath options. Oath of the Crown from Sword Coast Adventurer's Guide (SCAG), short summary is that its a paladin who champions civilization. Oath of Conquest, paladins who crush and subjugate their enemies and are sometimes called "Knight Tyrants", and Oath of Redemption, paladins who try to redeem everyone, from Xanathar's Guide to Everything (XGtE)

Of these extra Oaths. The Oath of Conquest would be close as it specifically states that some of these paladins consort with the Nine Hells and are ardent supporters of some archdevils.

Also, as others have mentioned, you can make a smaller purchase of just the class or subclass or race in a book instead of buying the whole book.

If you want more details on these other Oaths before you make your decision then let me know and I'll be happy to help.

If I can go with an evil paladin, that should give me what I'm looking for. From the basic rules, I got the impression that the paladin was a goodie, fighter/healer kind of noble class.

I definitely want the Player's handbook and Dungeon Master's guide, and maybe the Monster Manual.

The Paladin also gets a spell called "Find Steed" which but instead of being a beast can be either an fey celestial or more importantly for your character, fiend.

It's Int gets buffed to 6 and it understands a language of yours.

Can you give a TLDR of a blackguard/antipaladin as I started in 4e? So I know if I've given you any useful info.

If the intent is not necessarily being evil, but "just" not being a goodie-two-shoes with a penchant for not suffering idiocy/weakness, you could also look at the Oath of Conquest Paladin subclass from Xanathar's Guide to Everything.

To put into alignment terms, if the stereotypical Paladin could be considered Lawful Good, and a Black Guard/Oathbreaker Lawful Evil, the Oath of Conquest could be considered Lawful Neutral (think Judge Dredd): Law (or whatever version of law I follow) is to be applied end enforced regardless of any other variable, if there's a crime or a shortcoming, the appropriate punishment must be dealt.

Also, just to point this out, should your DM allow Feats (not a given since they are technically variant rules), you could also look at the Magical Initiate feat, that allows you access to a couple of cantrips and a lvl1 spell from any caster class you'd like. With it you could select Find Familiar from the Wizard list and decide with your DM that your famialiar is in the shape of a Fiend.

There's a prestige class version in 3.5 called the blackguard and an alternate paladin class in pathfinder called an antipaladin. Basically, the class I want is the one from pathfinder. You have to selfishly serve your own interests and doing something "good" for another person selflessly counts as violating your creed as an antipaladin.

"The second type of bond allows an antipaladin to gain the service of a fiendish servant. This functions as summon monster III, except the duration is permanent and the antipaladin can only gain the service of a single creature and that creature must either have the chaotic and evil subtypes or it must be a fiendish animal. Once selected, the choice is set, but it may be changed whenever the antipaladin gains a level. Upon reaching 7th level, and every two levels thereafter, the level of the summon monster spell increases by one, to a maximum of summon monster IX at 17th level. "

I was hoping for something like this so I could get an Erinyes(CR 6 I think) at some point. My character wouldn't be big on following laws, and would functionally be more of a Lawful Evil character leaning closer to neutral evil.

In 5e, prestige classes are mostly just the subclass that you pick (ex, arcane archer for fighter, assassin for rogue, etc).

edit: Paladins are not strictly lawful good in 5e, they can be of any alignment. At their core, they are a warrior class augmented with moderate divine spellcasting and party support auras, and smiting the bejesus out of stuff. Each paladin subclass has its own tenets to follow.

There is not an out of the box solution for what you want, that exactly matches the mechanics of the pathfinder class. Thematically you can get awful close though.

The tenets of the Oath of Conquest paladin

• Douse the Flame of Hope. It is not enough to merely defeat an enemy in battle. Your victory must be so overwhelming that your enemies’ will to fight is shattered forever. A blade can end a life. Fear can end an empire.
• Rule with an Iron Fist. Once you have conquered, tolerate no dissent. Your word is law. Those who obey it shall be favored. Those who defy it shall be punished as an example to all who might follow.
• Strength Above All. You shall rule until a stronger one arises. Then you must grow mightier and meet the challenge, or fall to your own ruin.

Or the description of an Oathbreaker paladin (which does not have tenets to follow anymore)

• An Oathbreaker is a paladin who breaks his or her sacred oaths to pursue some dark ambition or serve an evil power. Whatever light burned in the paladin’s heart has been extinguished. Only darkness remains.
• A paladin must be evil and at least 3rd level to become an Oathbreaker. The paladin replaces the features specific to his or her Sacred Oath with Oathbreaker features.

And then as a DM, I would allow you to add Summon Lesser Demons and Summon Greater Demon to the paladin spell list.

An Erinyes in 5e is CR 12, so pretty much nothing a player has access to short of Wish / Miracle has a chance to fetch one.

Would definitely recommend Conquest paladin with Magic Initiate, summon an Imp that you reflavor as a devil, or like was previously mentioned, use the Find Steed spell to create a Devil type creature as your mount. Conquest paladins still look the part but can be played as brutal, it is essentially their way or the high way. They are judge, jury, and executioner. 

I just read the Erinyes entry, they really got a power boost in 5E. What about planar ally? It would give me the option of having an erinyes I've been in communication with being sent by a patron, and I'd need to earn favor with it to keep it as a party member. I could go evil cleric, but I'm not sure how well they handle combat. Or if I could worship a non-deity for spells.

Paladins are unlike clerics in that they don't even require a diety. Your power stems from the strength of your Oath, which mechanically doesn't have to be to a God. In Ravnica for example, there aren't any gods.  So it'll play. 

Warlock pact of the chain will get you your imp/quasit pet and warlocks are on the lean side of half-casters. And warlocks can go very well with your blackguard idea. And hell if you go Hexblade you start out with medium armor, martial weapons, and shields.

Of course you could always just ask your DM to allow a companion (ranger style) or even a class feature swap out for the lock chain-pact feature.

And as far as buying the books, you can look up most anything through the wikis that are out there.

As far as a full up devil companion... You may want to look up the Aasimar and reskin the Aasimar guides feature with a devil theme. This with a warlock hexblade should get you close to what your after.

Quote from Antipaladinfever >>

I know I can get an imp or quasit familiar through spellcasting classes, but that's not what I'm looking for for this character.

I'm leaning towards either a cleric or warlock, I like the idea of more armor so I'm leaning towards cleric. I wonder how a DM would feel about a watered down Erinyes with maybe a CR 5-6? I'm iffy about Aasimar, even a fallen one.

How does the double scimitar work btw? Is it 1D4 damage on each attack or is the 2D4 for each side, so I'd roll 4 D4's with two successful hits?

I thought of Aasimar just because of the guide feature. I think it would be an easier way to have your Erinyes guide/companion.

And really I would have expected you to go Scourge for the radiant consumption as "hell fire" or necrotic damage instead of radiant. Hell fire/black mist pour out of your eyes and mouth and threaten to char you.

As to the scimitar you're in luck. They are d6 weapons now that are both light and finesse meaning you can duel wield with out feat or combat style and you can use your Dex modifier if it's better then your Str.

1. anyone may dual wield

2. the only weapons that may be dual wielded are those with the light property, both weapons must have this property

3. No 2 may be ignored if you take the feat Dual Wielder

4. attacking with the second weapon uses your bonus action

5. attacking with the second weapon does not add your ability modifier to damage except when...

6. except when using the fighter or ranger fighting style Two-weapon fighting

7. you may only draw or stow one of the weapons each turn unless No 6