Magus of the Arena

Text:

, : Tap target creature you control and target creature of an opponent's choice they control. Those creatures fight each other. (Each deals damage equal to its power to the other.)

Rulings:

• 2/1/2007 If either target leaves the battlefield before the ability resolves, the ability taps the remaining target, but no damage is dealt. If both targets leave the battlefield, the ability doesn’t resolve.
• 2/1/2007 Magus of the Arena’s controller always chooses their creature first.
• 2/1/2007 If an effect changes the targets of this ability, the second target can be changed to any creature the chosen opponent controls. The choice of opponent can’t be changed.
• 2/1/2007 Tapped creatures can be targeted. Tapping them again will do nothing, but they’ll still deal damage.
• 2/1/2007 If an effect changes the targets of this ability, the second target can be changed to any creature the chosen opponent controls. The choice of opponent can’t be changed.