UltraSunStreakbeam

A beam of brilliant light flashes out from your hand in a 5-foot-wide, 60-foot-long line. Each creature in the range will burn up turning them to instant ash. The  creature takes 25  radiant damage if you roll between 3-25 and if any other number it misses. 

You can create a new line of radiance as your action on any turn until the spell ends.

For the duration,the sun comes from your hands  and fires a huge beam of light energy able to kill the creatures.