Divine Obliteration

Shroud yourself in pitch black dark as you absorb all light in a 15ft sphere. After being charged for 3 actions, you can fire a massive beam of light, dealing 5d10+15 radiant damage and destroying any cover in its path within a 15 by 300 foot line. all adversaries hit by the beam are marked by the light, adding +4 radiant damage received for 5 rounds. Should you decide, you can charge this spell, multiplying its damage for every extra action spent to cast it, and extending the aoe width by 5ft and length by 100ft. It can be charged up to a maximum of 3 times and does not consume another spell slot, leading to some (hopefully) fun party play where the teammates protect the caster for an extended period of time for a one-shot blast. If charged more than 3 times, the spell will explode in the user's hand, dealing the resulting damage to all within a 50ft sphere. For both the cast line, and the overcharge explosion, make a Con saving throw, dc 10+the user's wis modifier/spellcasting modifier. on a success, the damage is halved.