Brilliant

This rune causes a weapon to transform into pure, brilliant energy. The weapon deals an additional 1d4 fire damage on a successful Strike, as well as 1d4 spirit damage to fiends and 1d4 vitality damage to undead.

On a critical hit, the target must succeed at a DC 29 fortitude or be Blinded for 1 round.

Activate—Shine Bright! ◆ (concentrate, light)

Effect You plunge your weapon into darkness to return the light. Attempt a counteract check with a counteract rank of 5 and a counteract modifier to end a magical darkness effect whose area is within reach of the weapon.