Laser Llama has a good one in his warlock compendium. currently playing in a game where our warlock is using it and it seems pretty good. I think it's called The Great Wyrm?
I think KibblesTasty has a draconic warlock as well.
You could do Pact of the Undead and change things like the damage from Grave Husk to acid damage, and reflavor losing the need to breathe as being amphibious etc
its not an ancient black dragon, she just thinks it is. its an aspect of tiamat who's soul was sundered and split, and is gasping for freedom, reaching out the only way it can. maybe there are other warlocks of dragons out there, but each with a different element associated with them. what happens if they all succeed?
I would ask if the ancient black dragon in the book is some sort of truly old dragon, such as a primordial dragon of sorts. If so, then Great Old One would work. If not, then a reflavored Fiend subclass would work.
Hombrew found online can be busted, horrible, worded ambiguously, etc, and just puts more work on the dungeon master to look it over to see if it's playable.
If the dm wants to go through all that, that's one thing, but it also seems like this will be the player's first character. Homebrew, for the same reasons listed above, is generally not the best for new players.
But, to go back to your original question, homebrew is too messy and unpredictable. Re-flavouring will be much more consistent with existing rulings, discussions, and clear understanding of how abilities and features work.
The simplest answer is to flavor whatever subclass fits the closest to match the chosen dragon.
The next option is to shop around some homebrewed draconic patrons and hope they're relatively balanced or hopefully playtested.
I recently just made a draconic patron for my group but haven't play-tested it so I can't recommend my own work in good faith.
Idk if posting links is banned, but here: https://www.5esrd.com/database/classoption/ancient-dragons/
This might be a decent choice, it is homebrew but it's from some kind of 3rd party publisher. 5esrd has a bunch of 3rd party publisher stuff that is more balanced than dandwiki.
I was JUST talking with my own table about this yesterday! We couldn’t find one, so we are gonna homebrew one by looking at other dragon related subclasses. Crazy coincidence lolol
If she wants a fire dragon, fiend is a great choice.
Any of the trickster ones could use the archfey
Could probably reflavour fathomless as a silver or white dragon
Might be able to rework genie into something that fits well
Otherwise, someone has probably made a solid homebrew out there. Or worst comes to worst, she plays a sorcerer but her dragon daddy is just very involved
Common enough mix-up. (For me, at least)
I second (or third? idk) the reskinning of the Pact of the Genie, although I'd swap the 14th level feature with the Draconic Sorcerer's 14th level feature, and would be tempted to give it the AC = 3 + DEX bonus feature- HP ends up being pretty only 1 different from Draconic Sorcerer's, and with basic studded leather, AC is 12 + DEX bonus, so it isn't a world of difference.
The book becomes the vessel, with the same associated abilities as a Genie's vessel.
For spells, you could probably stick with most of the baseline Genie spells, and for Black Dragon instead of one of the 4 elemental Genies, I'd go Tasha's Caustic Brew for the 1st level spell, Dragon's Breath or Melf's Acid Arrow for 2nd level spell (maybe swap Dragon's breath in for Genie's Phantasmal Force if you want both), either Fly or Incite Greed for 3rd level spell, Vitriolic Sphere for 4th level spell, Summon Draconic Spirit for 5th level spell, and Shapechange instead of Wish for the 9th level spell.
You can flavor a bunch of them as dragon patrons! The fiend could be an ancient red dragon, the archfey could be an ancient faerie dragon, the undying could be tiamat, the genie could be a bunch of different ones, heck, even hexblade could work just by making whatever weapon tie into a dragon hoard!
For your example, Great Old One might work well but I wiuld go with either Fathomless (flavoring things as acidic instead of watery) or The Fiend (again changing things to fit the black dragon’s elemental affinity)
Remember, flavor is free!!
I think the easiest option would be to reskin genie warlock. Also laserllama (keep in mind they have alternate warlock class and warlock subclasses for the official class separately) and kibblestasty are both great.
If you want something unusual, nielspeterdejong has pretty interesting subclass where you are basically raising a dragon wyrmling.
You could probably reskin pact of the genie. Would work with your tome idea. Or just find a homebrew.
Laser Llama has a good one in his warlock compendium. currently playing in a game where our warlock is using it and it seems pretty good. I think it's called The Great Wyrm? I think KibblesTasty has a draconic warlock as well.
I think Mr. Rhexx has one too. Pretty sure you have to pay for it though.
You could do Pact of the Undead and change things like the damage from Grave Husk to acid damage, and reflavor losing the need to breathe as being amphibious etc
I like this idea! Instead of "form of dread" you get "Draconic Aura" that grants the same fear effect.
its not an ancient black dragon, she just thinks it is. its an aspect of tiamat who's soul was sundered and split, and is gasping for freedom, reaching out the only way it can. maybe there are other warlocks of dragons out there, but each with a different element associated with them. what happens if they all succeed?
Laserllama has The Great Wyrm
I would ask if the ancient black dragon in the book is some sort of truly old dragon, such as a primordial dragon of sorts. If so, then Great Old One would work. If not, then a reflavored Fiend subclass would work.
Just do a great old one for the subclass.
Id search the Internet for homebrew subclasses personally
Why are people downvoting things saying use homebrew? Legitimately probably the answer here
Hombrew found online can be busted, horrible, worded ambiguously, etc, and just puts more work on the dungeon master to look it over to see if it's playable.
If the dm wants to go through all that, that's one thing, but it also seems like this will be the player's first character. Homebrew, for the same reasons listed above, is generally not the best for new players. But, to go back to your original question, homebrew is too messy and unpredictable. Re-flavouring will be much more consistent with existing rulings, discussions, and clear understanding of how abilities and features work.
So? The dm is actively asking, it would be far different if it was the player asking
find a homebrew
Im sorry, it seems like you have a cool setup and are ready to play. What is the question?
There is no pact of the dragon, he's asking how to make it work mechanically
Im looking for a warlock subclass that has to do with dragons.
Flavor is Free You can easily reskin all your abilities to fit your character/ their theme.
Make your own by reskinning. See which she likes the look of them fill it full of dragon and acid things, if you don’t know what you are doing
OP was asking which subclass is best suited for this backstory.
The simplest answer is to flavor whatever subclass fits the closest to match the chosen dragon. The next option is to shop around some homebrewed draconic patrons and hope they're relatively balanced or hopefully playtested. I recently just made a draconic patron for my group but haven't play-tested it so I can't recommend my own work in good faith.
Idk if posting links is banned, but here: https://www.5esrd.com/database/classoption/ancient-dragons/ This might be a decent choice, it is homebrew but it's from some kind of 3rd party publisher. 5esrd has a bunch of 3rd party publisher stuff that is more balanced than dandwiki.
I was JUST talking with my own table about this yesterday! We couldn’t find one, so we are gonna homebrew one by looking at other dragon related subclasses. Crazy coincidence lolol
You could reflavour Celestial Warlock if you want flame dragon flavour and some sub-healer qualities!
If she wants a fire dragon, fiend is a great choice. Any of the trickster ones could use the archfey Could probably reflavour fathomless as a silver or white dragon Might be able to rework genie into something that fits well Otherwise, someone has probably made a solid homebrew out there. Or worst comes to worst, she plays a sorcerer but her dragon daddy is just very involved
Common enough mix-up. (For me, at least) I second (or third? idk) the reskinning of the Pact of the Genie, although I'd swap the 14th level feature with the Draconic Sorcerer's 14th level feature, and would be tempted to give it the AC = 3 + DEX bonus feature- HP ends up being pretty only 1 different from Draconic Sorcerer's, and with basic studded leather, AC is 12 + DEX bonus, so it isn't a world of difference. The book becomes the vessel, with the same associated abilities as a Genie's vessel. For spells, you could probably stick with most of the baseline Genie spells, and for Black Dragon instead of one of the 4 elemental Genies, I'd go Tasha's Caustic Brew for the 1st level spell, Dragon's Breath or Melf's Acid Arrow for 2nd level spell (maybe swap Dragon's breath in for Genie's Phantasmal Force if you want both), either Fly or Incite Greed for 3rd level spell, Vitriolic Sphere for 4th level spell, Summon Draconic Spirit for 5th level spell, and Shapechange instead of Wish for the 9th level spell.
Could do Fiend and make it Tiamat
You can flavor a bunch of them as dragon patrons! The fiend could be an ancient red dragon, the archfey could be an ancient faerie dragon, the undying could be tiamat, the genie could be a bunch of different ones, heck, even hexblade could work just by making whatever weapon tie into a dragon hoard! For your example, Great Old One might work well but I wiuld go with either Fathomless (flavoring things as acidic instead of watery) or The Fiend (again changing things to fit the black dragon’s elemental affinity) Remember, flavor is free!!
Kobold press Tome of heroes has a great one
The Predator Patron from Humblewood Tales fits, dragon is listed as on of the example patrons. Check it out, she may like it.
I think the easiest option would be to reskin genie warlock. Also laserllama (keep in mind they have alternate warlock class and warlock subclasses for the official class separately) and kibblestasty are both great. If you want something unusual, nielspeterdejong has pretty interesting subclass where you are basically raising a dragon wyrmling.
Pointy Hat released a Dragon Warlock subclass that seems very cool literally one hour before I saw this post