Tracer, Rebellious Speedster

{u}{u}: Exile Tracer, then return her to the battlefield with X charge counters on her, where
X is the number of charge counters she had the last time she was on the battlefield plus one.
{u}{u}{u}{u}: Return Tracer to your hand. If Tracer
had six or more charge counters on her, target opponent sacrifices a creature and then taps each other creature they control. That player takes an additional turn after their next turn.