Tick of the Clock

You twist a being's timeline against itself. Make a melee spell attack against a creature you can reach. On a hit, you conjure an ethereal clock above its body. Each time it ticks, the target takes 2d8 force damage. The clock ticks immediately upon the casting of this spell, at the start of the creature's next turn, and again at the start of your next turn.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 for every two slots above 2nd.