Tracer

Haste, first strike
Tracer enters with 3 charge counters on it.
At the beginning of each upkeep, if Tracer has less than 3 charge counters, put a charge counter on it.
{2},Exile Tracer: Return it to the battlefield under your control at the beginning of the next end step.

Remove 2 charge counters from Tracer: Choose one —
•Tracer deals 2 damage to any target that was dealt damage this turn.
•Tracer phases out.
•Scry 3.