Chrono Siphon

You choose a single target within range. Outstretching your hand you siphon the very seconds of the targets life. The target must make a constitution saving throw. They take 2d8 Force damage (Half damage on success). Any damage dealt is returned to  the caster as health.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 for each slot level above 3rd