D&D 5th: Demon Tower of Madness
Casting Time: Swift
Duration: 1 minute
You can cast this spell when you hit with a melee weapon attack on your turn. A pulse of green light flashes from your weapon, and the attack deals 5d10 extra force damage to the target. Additionally, the target must make a Constitution saving throw or take 2d10 force damage at the start of each of its turns until the spell ends. The spell ends when the target makes a successful saving throw against it. If the target is reduced to 0 hit points by this spell, the target is disintegrated.