Otherworldly Poisoner

General Feat (Prerequisite: Level 5+ Feat: Poisoner)

You gain the following benefits.

Ability Score Increase. Increase your Dexterity or Intelligence score by 1, to a maximum of 20.

Deadly Poison. When you make a damage roll that deals poison damage you may have it ignore immunity to poison damage but deal 1 less damage per dice you rolled. 

Powerful Poison: Whenever you case a creature to make a saving throw against being poisoned, if the creature is immune to the poison condition they lose that immunity but make the saving throw with advantage for that effect.

Internal venom:  When you make an unarmed strike you can deal 1d4 + con modifier poison damage instead of bludgeoning.