Arcane Syphon

The touch of your shadow-wreathed hand can siphon life force from others to restore magic. Make a melee spell attack against a creature within melee range. On a hit, the target takes 1d6 damage and the caster adds that many leveled spell slots (a 6 restores 2 level 3 slots or 1 level 6 slot). Until the spell ends, you can make the attack again on each of your turns as an action.

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