I want to make a build with as many breath attacks as possible. What I have come up with so far is Dragonborn and draconic ancestry sorcerer. I would prefer if it would end out being the like avatar of breath attacks. Preferably without potions of fire breath or whatever the potion is called.
Just stick with being a Dragonborn Sorcerer
There are 13 types of damage: Acid, Bludgeoning, Cold, Fire, Force, Lightning, Necrotic, Piercing, Poison, Psychic, Radiant, Slashing, and Thunder. We'll rule out Bludgeoning, Piercing, and Slashing, because that's just weird for a breath weapon. That leaves ten: Acid, Cold, Fire, Force, Lightning, Necrotic, Poison, Psychic, Radiant, and Thunder.
First, choose Gem Dragonborn as your race. Depending on your heritage, you can get one obscure breath weapon:
I would take Topaz for the Necrotic breath weapon.
At third level, take Dragon's Breath:
You touch one willing creature and imbue it with the power to spew magical energy from its mouth, provided it has one. Choose acid, cold, fire, lightning, or poison. Until the spell ends, the creature can use an action to exhale energy of the chosen type in a 15-foot cone...
That will take care of four. In Tasha's Guide to Everything, there are additional Metamagic's a sorcerer can take. One is called Transmuted Spell:
When you cast a spell that deals a type of damage from the following list, you can spend 1 sorcery point to change that damage type to one of the other listed types: acid, cold, fire, lightning, poison, thunder.
That adds Thunder the list of possibilities. Since it was brought up in comments, if the Metamagic doesn't work on the dragon's breath spell, then just get the thunderwave spell instead. It's cone shape would match a breath weapon.
Which leaves Force, Psychic, and Radiant.
At 11th level Sorcerer, take the 6th level spell, Sunbeam for radiant damage:
A beam of brilliant light flashes out from your hand in a 5-foot-wide, 60-foot-long line. Each creature in the line must make a Constitution saving throw. On a failed save, a creature takes 6d8 radiant damage and is blinded until your next turn. On a successful save, it takes half as much damage and isn't blinded by this spell. Undead and oozes have disadvantage on this saving throw.
Admittedly, the spell says it emanates from your hand, but I'm sure a DM would allow you say it shoots out from your mouth instead.
At 13th level, take Draconic Transformation:
With a roar, you draw on the magic of dragons to transform yourself, taking on draconic features. You gain the following benefits until the spell ends:
Breath Weapon. When you cast this spell, and as a bonus action on subsequent turns for the duration, you can exhale shimmering energy in a 60-foot cone. Each creature in that area must make a Dexterity saving throw, taking 6d8 force damage on a failed save, or half as much damage on a successful one.
At 17th level, take Psychic Scream which is pretty darn close to a "psychic breath weapon":
You unleash the power of your mind to blast the intellect of up to ten creatures of your choice that you can see within range. Creatures that have an Intelligence score of 2 or lower are unaffected.
Each target must make an Intelligence saving throw. On a failed save, a target takes 14d6 psychic damage and is stunned. On a successful save, a target takes half as much damage and isn’t stunned. If a target is killed by this damage, its head explodes, assuming it has one.
And with that, you can "breath" every damage type (minus the physical weapon trifecta).
You can get almost all of the damage types at level 5
To start with, let's make an Order of Scribes wizard which gives us access to Awakened Spellbook:
When you cast a wizard spell with a spell slot, you can temporarily replace its damage type with a type that appears in another spell in your spellbook, which magically alters the spell's formula for this casting only. The latter spell must be of the same level as the spell slot you expend.
Starting at 3rd level, we can then cast dragon's breath (which already has access to acid, cold, fire, lightning, or poison), and modify it to many other damage type via the following spells:
- Bludgeoning via dust devil
- Psychic via phantasmal force
- Slashing via cloud of daggers
- Thunder via shatter
Through an upcasted dragon's breath, we also get access to necrotic and radiant with spirit shroud.
Finally, we'll want to be in the Wildemount setting (or have a DM who is willing to let us use setting specific spells) to help with missing out on force via the dunamancy spell pulse wave.
You should also try to scribe the spells erupting earth and thunder step to supplement upcasted dragon's breath for the bludgeoning and thunder damage types that you only have 2nd level spells for.
With this, you only miss out on piercing damage breath weapons, and upcasted psychic and slashing breath weapons.
How to get the most out of dragon's breath
Depending on how your DM interprets the twinning effects in the game, you can get a lot of value through twinning dragon's breath. (see these Q&As: 1, 2 for some examples of the layers having to do with twinning effects).
If you can't twin dragon's breath, stick with wizard and see my final section for some key spells to pick up that help with Awakened Spellbook. If you can twin dragon's breath, the best method is the find steed and find greater steed spells which say:
While mounted on [your steed], you can make any spell you cast that targets only you also target [your steed].
This essentially doubles the effectiveness of your breath weapon since it will be much more potent than the steed's regular attacks.
The best way to get these spells is to multiclass as a College of Lore bard which will maintain your full caster progression in terms of spell slots. By level 11, you will have find steed through Additional Magical Secrets, and find greater steed by level 15.
I strongly recommend picking up the Mounted Combatant feat to help keep your mount alive at these higher levels (speaking of, I'd probably play a Mountain Dwarf. Medium armor plus the shield spell can make you reasonably durable).
With the free twinning effect, a 2nd or 3rd level dragon's breath becomes as effective as a 5th or 7th level dragon's breath that has only one target. Additionally, you will have access to some very high level spell slots to upcast with when acid, cold, fire, lightning, or poison is acceptable.
Finishing the build
I'd recommend returning to wizard after find greater steed to get some higher level wizard spells so that you can use with Awakened Spellbook. At 17th level (with 4th level wizard spells), you have:
- Bludgeoning via Evard's black tentacles
- Force via the dunamancy spell gravity sinkhole
- Necrotic via blight
- Psychic via phantasmal killer
- Radiant via sickening radiance
- Thunder via elemental bane
...and at 19th level (with 5th level wizard spells), you have:
- Bludgeoning and Force via Bigby's hand
- Necrotic via enervation
- Psychic via synaptic static
- Radiant via dawn
If your DM decided that you can't twin dragon's breath, below are the rest of the Awakened Spellbook spells for upcasting purposes since you are a higher level wizard.
|investiture of wind
|dunamancy: dark star
|dunamancy: ravenous void
|circle of death
|finger of death
|Abi-Dalzim's horrid wilting
|dunamancy: time ravage
|crown of stars
Starting at 7th level spells and higher, you may want to cast draconic transformation rather than dragon's breath (unless you need the dragon's breath damage types); less damage but more utility and much more range. For an 8th and 9th level draconic transformation you can gain access to the damage types from dragon's breath via Awakened Spellbook thanks to illusory dragon and prismatic wall.