When you finish a Long Rest, you can strike one of the following bargains with your infernal masters. You can also discuss new bargains with your GM. The bargain lasts until you finish a Long Rest.
Blindsight and Blindness
You have Blindsight with a range of 30 feet. Beyond this range, you have the Blinded condition.
Damage and Actions
Once on each of your turns, you can choose to take Necrotic damage equal to twice your Investigator level to take an additional action. This action can only be used to take only the Attack (one attack only), Dash, Disengage, Hide, or Utilize action.
Resistance and Vulnerability
Choose two of the following damage types: Acid, Cold, Fire, Lightning, Poison, Psychic, and Thunder. You have Resistance to the chosen damage types. The GM chooses another type from the list; you have Vulnerability to that damage type.