Aura the guillotine

Haste
{t}, choose target creature an opponent controls. If that creatures power is less than
Aura the guillotines power, gain control of that creature. If that creatures power is greater than Aura the guilltoines power, that creatures controller takes control of Aura the guillotine. Activate only during your precombat main phase

each player may activate abilities of Aura the guillotine