Trust in the Guide Star

You squeeze tight your eyes and call upon the Purple Star to grasp your mind and guide your strike true.

A cone of brilliant radiance descends on a creature that you can see within range and it must make a Dexterity saving throw. It takes 2d10 radiant damage on a failed save, or half as much damage on a successful one. The target gains no benefit from invisibility or cover for this saving throw.