Thousand Cuts

Make an attack roll against target creature with in 120ft . On a hit deal (2d4) Slashing damage and mark the target with a stack of Thousand Cuts. The target can gain up to a maximum of 10 stacks. For each stack the creature has at the start of it's turn it takes Slashing damage equal to the stacks of Thousand Cuts. 

Anytime affected creature takes non-magical physical damage add a stack of Thousand Cuts. When it's the affected creature's turn remove half the stacks of Thousand Cuts rounded down. If the affected creature loses all stacks of Thousand Cuts this spell ends, the spell also ends if concentration is lost.

Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the maximum stacks of Thousand Cuts increase by 5 for every level above 1st.