What happens if I target Zada, Hedron Grinder with a spell and then donate it to an opponent?

Question

What happens when I target Zada, Hedron Grinder (say with a Traitor's Roar or Threaten, but not both), then before the ability resolves (creating the copies), donate (using say Bazaar Trader) to an opponent? Does the ability resolve?

If it does, since it's under an opponent's control when it does, are the copies made for their creatures or mine?

And who owns the copies since the Zada is under an opponents control?

Assuming Zada does resolve and depending on the answers above I understand one of the following would apply:

• If I control the spell copies, but the spells target the opponents creatures, then this is the most useful as Threaten and Traitor's Roar (or any burn or kill spell) would operate as intended.

• If the spell copies are the opponents (because the copies were generated by the newly acquired opponent's Zada), and the spell targets the opponents creatures, then Threaten really only temporarily gets me Zada back. Still, Traitor's Roar (or destroy/burn spells) would still function as intended.

• If I control the spell copies and the spells target my creatures then I would temporarily get Zada back and Traitor's Roar would hurt me.

• If the spell copies are the opponents, but target my creatures, then the oponent would temporarily gain control of my creatures (except for Zada, which would come to me). And Traitor's Roar would hurt me.

If any of these assumptions are wrong, please clarify how it would work. (I'm basically trying to get effects to target an opponents creatures, similar to how the Ink-Treader Nephillim would, but keep it mono color. Or if I temporarily give my creatures to an opponent, then I think I could have some fun with that too.)

Answer 1

Zada's ability will still resolve, and you will still be the controller of that ability, so donating Zada will not make any difference.

112.8. The controller of an activated ability on the stack is the player who activated it. The controller of a triggered ability on the stack (other than a delayed triggered ability) is the player who controlled the ability’s source when it triggered

Emphasis mine. Zada's ability triggers as soon as you finish casting Traitor's Roar. It then goes on the stack, as an ability controlled by you, before you get a chance to respond with something like Bazaar Trader's ability.

If you did respond with Bazaar Trader's ability, then after that resolves, Zada's ability would still resolve like normal, and you would still be the one affected by it. You would be the controller of the copies of the spell, and they would target your creatures.

111.2. A spell’s owner is the same as the owner of the card that represents it, unless it’s a copy. In that case, the owner of the spell is the player under whose control it was put on the stack. A spell’s controller is, by default, the player who put it on the stack. Every spell has a controller.