Patient Duelist

At the beginning of each end step, put a +1/+1 counter on Patient Duelist if you dealt damage to
an opponent this turn.
Whenever Patient duelist attacks, if it has a
+1/+1 counter on it, it gains first strike. If it has
at least two +1/+1 counters, it also gains menace.
If it has three or more +1/+1 counters, it gains
double strike. Remove all +1/+1 counters from
Patient Duelist.