You are born with a disgusting power, with many disgusting possibilities.
Cursed Energy
Starting at 1st level, you can harness your negative feelings into a usable source of energy, called cursed energy. These feelings can be harnessed into attacks or abilities. The number of cursed energy you possess is based on your class, some classes use a modifier that being charisma or wisdom (Player’s choice)
Your cursed energy DC is 8 + user cursed energy ability modifier + proficiency bonus.
Vermin of Disaster
Beginning at 1st level, as an action for 2 cursed energy you create an Insect Swarm in a space you can see within 5 ft of you. You can command the swarm as a bonus action, otherwise it takes the dodge action. Your Insect Swarm is made up of actual insects created from your cursed energy, not shikigami and you can only have one Insect Swarm summoned at a time.
Earthen Insect Trance
At 3rd level, your mastery over insects has grown. You can have a number of Insect Swarms summoned equal to your proficiency bonus and can command any number of them as a bonus action.
Additionally, you gain access to an insect shikigami with a large pouch. As an action, you can summon up to 2 shikigami, spending 2 cursed energy per shikigami to summon them in an unoccupied space within 10 ft of you. You can command the Shikigami and Insect Swarm as part of the same bonus action.
Almighty Swarm
At 6th level, you have learned the power of the almighty swarm. As part of the bonus action to command your Insect Swarms, you can order different swarms to move closer and combine into one Vermin Swarm if within 5 ft of each other, becoming 1 size larger for every additional swarm. The Vermin Swarm gains the combined hit points and damage dice of all the swarms together. The individual Insect Swarms that make up the Vermin Swarms still count against your maximum number of controlled swarms.
Parthenogenesis
At 11th level, you have learned that your instinctual hunger is not without reason, but exists to stimulate the desire to multiply. As an action for 8 cursed energy, you create an insect egg affixed to a wall/ceiling. The cost to create the egg decreases by 1 CE per creature devoured by you or a swarm in the last 8 hours (min cost 1).
The egg has an AC equal to your Cursed Energy save DC and hit points equal to twice your level. If you die within an hour of creating the egg, it births an identical copy of you from it with current hit points equal to half your hit point maximum. Your cursed energy is passed on after your death, giving your new body your remaining cursed energy from when you died. You do not regain any gear you had beforehand.
Domain Expansion: Brood Cathedral of the Crawling God
Finally at 18th level you have learned to expand your domain. At initiative 20, up to 3 creatures of your choice within your domain take 6d10 necrotic damage as eggs fester and burst from their skin.
A creature that dies within your domain is devoured and becomes an Insect Swarm. This Insect Swarm does not count against your maximum number of controlled swarms until the domain ends.
Reversal
反転 How to gain this: Cursed Technique Reversal →
Stillbirth Colony
You have learned the reversal of your technique. Rather than consuming and multiplying, you suppress the biological instincts of others. As an action for 6 CE, you create a 15 ft aura centered on you for 1 minute. A creature that starts their turn within this aura must make a Constitution saving throw whenever they attempt to gain temporary hit points or regain hit points. On a failed save, their body rejects the effect and the action and cursed energy cost used to give the temporary hit points or hit points are wasted. A creature that fails this saving throw by 5 or more has their body begin to shut down, giving them disadvantage on Constitution saves and wasting their bonus action and reaction until the end of their next turn.