Boon of Otherworldly Forms

You can tap into a extremely powerful version of yourself to increase your capabilities.

Demonic Resistance.  You gain resistance to Radiant and Necrotic damage.

Divine energy.  You can replace the damage type of any of your attacks with Force, Necrotic or Radiant damage.

Protection from Death.  Once per long rest, when you or a person you can see drops to 0 hit points, you can cause them to immediaty go to half of their hit point maximum