Bloodletter

You touch a nonmagical weapon. Until the spell ends, the first creature hit by the weapon must succeed on a Constitution saving throw or receive a festering wound. A creature with a festering wound takes 2d6 Necrotic damage at the start of each of its turns for the spell’s duration. A creature can only have one festering wound at a time.

If the creature receives healing, the spell and recurring damage end.

Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot above 2.