Arcane Desiccation

Make a melee spell attack. On a hit, you deal 4d8 necrotic damage and, if the target has spell slots, it loses spell slots with a maximum combined level of 9, and you regain 1d4 hit points per level of spell slot destroyed. If you cast this spell at a higher level, the maximum combined level increases by 2 per level of spell slot above 7th.