Belligerent Shadow of Bobastis

As a bonus action, you summon the presence of Bobastis the Corruptor on your own body, allowing his power to bolster your magical prowess while you cry blood from your now deep crimson eyes. In exchange, you offer a spell of 1st level or higher from your prepared spell list that does damage. When you do so, you cannot cast the chosen spell until this one ends. 

The dark presence in you provides the following boons to empower your spellcasting. You may use a boon as a reaction. Each time you decide to use a boon, you suffer psychic damage equal to twice your proficiency bonus that ignores any resistances or immunities. You also receive the same amount of damage at the end of each round that you didn't use a boon on. After you have used boons three times, the spell ends and you are healed by the total psychic damage you received.

• Boon of Lethality. You may reroll a spell attack you make, keeping the highest score of the two. You may reroll a 1 only once.
• Boon of Violence. The next spell you cast that does damage receives two additional damage dice. You may reroll a 1 only once.
• Boon of the Profane. The next saving throw that a spell forces upon enemies is rolled with disadvantage.
• Boon of the Mind. The next Concentration check you roll has advantage. You may reroll a 1 only once.

If the spell ends early by a dispel magic spell or similar effects, you take psychic damage equal to three times your proficiency bonus and your hit point maximum is lowered by that same amount. This effect can be nullified by taking a long rest or receiving the effects of a greater restoration spell or similar effects.

At higher levels. An extra boon can be used when casting this spell at 6th level, and two extra boons at 8th level.