Evangelize
Sorcery
Buyback 
(You may pay an additional as you cast this spell. If you do, put this card into your hand as it resolves.)
Gain control of target creature of an opponent's choice they control.
Randy Elliott
Time Spiral (TSP)
• #16Rulings
When you put the spell on the stack, you choose an opponent, then that opponent chooses the target. This is not a choice made on resolution.
(wotc • 2006-09-25)
The target of the spell is a creature the chosen opponent controls. As Evangelize resolves, if the target isn’t a creature controlled by the chosen opponent, Evangelize won’t resolve. If Evangelize’s target is changed (via Shunt, for example), the new target must be a creature controlled by the chosen opponent.
(wotc • 2006-09-25)
Rulings
When you put the spell on the stack, you choose an opponent, then that opponent chooses the target. This is not a choice made on resolution.
(wotc • 2006-09-25)
The target of the spell is a creature the chosen opponent controls. As Evangelize resolves, if the target isn’t a creature controlled by the chosen opponent, Evangelize won’t resolve. If Evangelize’s target is changed (via Shunt, for example), the new target must be a creature controlled by the chosen opponent.
(wotc • 2006-09-25)