Might Makes Right

Text:

At the beginning of combat on your turn, if you control each creature on the battlefield with the greatest power, gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and this turn.)

Rulings:

• 7/18/2014 “Each creature on the battlefield with the greatest power” may be a single creature if each other creature has less power.
• 7/18/2014 The ability will trigger only if you control each creature on the battlefield with the greatest power as the beginning of combat step begins. If another player controls a creature with the greatest power or tied for the greatest power at that time, the ability won’t trigger at all.
• 7/18/2014 The ability will check its condition again as it tries to resolve. If, at that time, another player controls a creature with the greatest power or tied for the greatest power, the ability won’t do anything.
• 7/18/2014 The ability can target any creature an opponent controls, not just one that’s tapped.
• 7/18/2014 Gaining control of a creature doesn’t cause you to gain control of any Auras or Equipment attached to it.