Time Shifter

{5}{t}: Take an extra turn after this one. Activate this ability only on your turn. If this is the second time you have activated this ability since it came under your control, instead exile a legendary creature you control. If you don't, exile Time Shifter. If you do, take an extra turn after this one, and target opponent gains control of Time Shifter
Once it realizes you have already witnessed it's power, it banishes you and finds a new master.