Boon of Blazing Dawn

Boon of Blazing Dawn
Feat
Prerequisite: Level 19

You gain the following benefits.
Beloved of the Sun.
You have Immunity to Radiant damage.
Blazing Strike.
When you hit a creature with a weapon attack, the damage can be Radiant or the weapon's normal damage type (your choice).
Burst of Sunlight.
Once per turn when you hit a creature with an attack that deals Radiant damage, you can emit Bright Light in a 30-foot radius from yourself and Dim Light for an additional 30 feet until the start of your next turn. This light is sunlight.

Source: Astarion's Book of Hungers (ABH), page 11