Incorporeal:  Creature must assume corporeal form to attack but may, as an action, become incorporeal, having no physical form except for two glowing eyes.  In this form, creature is resistant to slashing, piercing, bludgeoning, and all other non-magical attacks.  Creature is also resistant to all magical attacks requiring an attack roll.

Undead Fortitude:  If damage reduces creature to 0 hit points, it must make a Constitution saving throw with a DC equal to the damage it was dealt beyond what would bring it to 0 hit points, unless the damage is radiant or from a critical hit.  On success, the creature drops to 1 hit point instead.

Example:  If the creature has 15 hit points, but sustains 22 damage, it must make save with DC of 7.   If it succeeds, it now has 1 hit point 

Undead Nature:  Does not require air, food, drink, or sleep.

Sanduwill Temple:  If creature is in the Sanduwill Temple, they are able to draw from the stone to channel an additional 5 (1d6+2) radiant damage per successful attack.