Mark of Gluttony

Your Constitution score increases by 1 to a maximum of 20.

You have advantage on saving throws against ingested poisons.

Gluttony:

You have embraced the insatiable hunger within, allowing you to consume not only flesh, but the very essence of your foes. Through this dark power, you gain the ability to permanently steal abilities from those you devour.

Features:

1. Essence Consumption: When you reduce a creature of CR 1 or higher to 0 hit points, you can choose to consume its essence as a bonus action by devouring part of the creature's body. Once you do this, you permanently steal one of the following abilities from the creature:

   - Skill Proficiency: Choose one skill proficiency the creature had. You gain proficiency in that skill. If you already have proficiency, you gain expertise (double your proficiency bonus).

   - Language: If the creature knew a language, you may permanently learn one language the creature knew.

   - Feature or Spell: You may permanently steal a minor feature, racial trait, or spell the creature had, such as darkvision, a breath weapon, or a spell of 3rd level or lower. You can cast this spell or use the ability using your Constitution as the spellcasting ability. This feature cannot grant you class abilities or legendary actions.

2. Limit of Gluttony: You can permanently retain a number of stolen abilities equal to your proficiency bonus + Constitution modifier. If you attempt to steal another ability beyond this limit, you must choose an existing stolen ability to replace.

3. Sustenance of Power: Whenever you consume a creature’s essence using this feat, you gain temporary hit points equal to half the creature’s hit point maximum. These temporary hit points last for 24 hours.

Once you use Essence Consumption, you can’t do so again until you finish a long rest.

Ravenous:

The world has become your lavish feast, formed to cater to you and you alone. You cannot become full from food, and can eat endlessly. You will eternally be afflicted with a pain in your abdomen to remind you to eat. If the character goes without eating for 7 days, however... you can perish on the spot. (Will receive a point of exhaustion that doesn't reset intill a pound of flesh has been consumed)