Death's Feathered embrace

The caster draws upon Death itself to shield them from damage.

Upon casting, the user is cloaked in a shroud of Necrotic energy, with crimson-and-black feathers slowly drifting down around them.

The caster gains resistance to Necrotic damage and +3 AC until the end of the next turn, and gains an extra 1d4 on all Necromancy spell rolls.

When cast at 5th level or higher, those who attempt to attack target must take 1d4 Necrotic damage on a successful hit.
The hit die for the necrotic damage goes up by one every two levels. When cast at 9th level, it inflicts 4d4 Necrotic damage plus the caster's spell casting modifier.