Infested Catalyst

Infested Catalysts are usually created through experimentation. Any kind of creature could be any kind of catalyst, however not a lot manage to survive their creation. Often masters of elements and especially poisons and viruses. An Infested Catalyst is often on the void between life and death, sacrificing their life force to defeat their foes.

Poisonous Blood

Your unnatural creation has infected your bloodstream. When you choose this subclass at 1st level, you gain a resistance to poison attacks and you can throw your blood at your enemies. You also gain the acid splash cantrip when you select this subclass, which you can cast twice before needing a long rest. 

Infested Amp

You know how to use your uncommon origin to your advantage. At 1st level, you gain the ability to spend health equal to the level of a spell slot + 1 to add 1 extra dice to the attack.

Additionally, when you reach 2nd level, you can spend health in place of sorcery points.

Adaptable Blood

Your naturally infected bloodstream has adapted to outside forces. At 6th level, whenever you take poison damage while your current health is lower than your maximum, you can expend one sorcery point to heal from that damage instead. You can use this feature up to two times per long rest.

Acidic Guard

At 14th level, you learn how to control your blood and make it take shape. When you take damage, you can spend 1/4 of your maximum health (rounded up) to boost your AC by +6 for the next minute.

Additionally, any poison damage you deal can be swapped for acid damage (or vice versa), and you can spend two sorcery points to change other elements to either poison or acid. You can only spend sorcery points for this feature two times per long rest, but can swap poison and acid damage freely.

Catalytic Bomb

Beginning at 18th level, you have mastered your infestation, and can expel it at violent levels. By spending half of your sorcery points or maximum health (rounded down) to create a large acidic explosion, dealing 6d8 acid damage to everything in a 15 ft sphere around you. Everybody hit by this attack must make a constitution saving throw. On a success, nothing else happens. On a fail, the creature takes 3d8 poison damage at the start of it's next three turns. Additionally, you take 1d6 poison damage at the start of your turn for the next minute.

Additionally, all acid/poison damage you deal unrelated to this feature is doubled (after rolling).