Feats

Boon of Exquisite Radiance

Prerequisite
Level 19+
Ability Score Increase
+1 to any ability score (max 30)
Source
FRHoF

You gain the following benefits.

Eternal Rest

Creatures you reduce to 0 Hit Points can't become Undead.

Powerful Radiance

When you make a damage roll that deals Radiant damage, you can instead use the highest number possible for each damage die. Once you use this benefit, you can't do so again until you finish a Long Rest.