Player A has stardust and face down torrential tribute. Player B has face up zenmaines with 1 material. Its player B's turn. B MST the face down. A uses stardust. B summons tour guide and s.summons another tour guide. A uses torrential tribute, thus destroying the tour guides and a material from zenmaines. B end's his turn. Does stardust come back then zenmaines can target him or does he have to target himself then stardust comes back?

Zenmaines effect is continuous so you can activate it any time during the end phase. Player B must activate Zenmaines effect destroying Stardust. Stardust can negate and destroy zenmaines. Stardust can come back as long as it wasn't summoned by Road.

so dust always come back before zenmaines eff?

I'm pretty sure it does.

Inb4 corrected?

yeah, good question, i want to know the answer too..

A. SD return, Zenmaines target SD, SD negate and destroy Zenmaines, SD return again.

or

B. Zenmaines target itself, it destroy, SD return.

or

C. SD return and Zenmaines target itself simultaneously.

any official answer?

Hmm. No.

Player B's the turn player so he gets priority. And he gets to choose if he wants to summon Stardust first, since it's not mandatory. If not, he passes priority, and player A's Zenmaines' effect activates, and A decides which card to destroy. If B decided to Special Summon Stardust, A can target it with Zenmaines' effect (Which is a trigger effect, btw, Akeno), and A can use Stardust's effect to negate it. If he does, Stardust is tributed and Zenmaines gets destroyed. Then Stardust is Special summoned again.
If player B doesn't want to Special Summon Stardust, he can pass priority and player A must target 1 card to destroy with Zenmaines' effect. Then player B cannot special summon Stardust anymore.

good answer,
but what if player A is the turn player? I think the same case will happen even whoever turn it is, the Zenmaines's player still at lost, and SD still can be summon, even whoever turn player, right?

Player A can decide in which order to activate each effect.
So he can either:
A) Pass priority, B decides if they want to SS Stardust, then Zenmaines' effect activates, because There's nothing else to be done. Then Stardust is tributed, and Zen destroyed.
B) Resolve Zenmaines' effect, destroy itself, then player B decides whether he wants to SS Stardust or not.

oh, now i see the difference.

Question has been answered, topic locked.