Sower of Temptation blocking another Sower of Temptation

[Cyberpunker]

If my opponent casts a sower on my goyf. But I cast another sower to steal the goyf back. Now I attack with my creatueres, he blocks my sower with his sower. Who gets the goyf? I think I do because his sower's ability stacks too right?

[Godder]

These are a lot easier when people post Oracle text. The relevant bit:

When Sower of Temptation comes into play, gain control of target creature as long as Sower of Temptation remains in play.

The Sowers go the graveyard at the same time, but the important part here is that there's no "when Sower leaves play, return creature to its owner" or anything like that i.e. it's not a triggered ability. Rather, when the Sowers die, the creature ('Goyf in the example) simply stays put because there are no control effects in play. If your Sower died but his lived somehow, 'Goyf would now be controlled by your opponent, but since neither Sower survive, nothing happens.

[Mr. Type 4]

What about Merieke Ri Berit?

Oracle:
Merieke Ri Berit doesn't untap during your untap step.
 : Gain control of target creature as long as you control Merieke Ri Berit. When Merieke Ri Berit leaves play or becomes untapped, destroy that creature. It can't be regenerated.

In a multiplayer game if a third party steals Merieke from me (and I had taken someone else's creature) do I have to give the creature I took back? If they steal Merieke and then sacrifice her, does the stolen creature get destroyed?

[RJ]

What about Merieke Ri Berit?

Oracle:
Merieke Ri Berit doesn't untap during your untap step.
 : Gain control of target creature as long as you control Merieke Ri Berit. When Merieke Ri Berit leaves play or becomes untapped, destroy that creature. It can't be regenerated.

In a multiplayer game if a third party steals Merieke from me (and I had taken someone else's creature) do I have to give the creature I took back? If they steal Merieke and then sacrifice her, does the stolen creature get destroyed?

This is a weird wording, but it seems like if you steal a creature and another player steal Merieke, the stolen creature goes back and will still be destroyed when she untaps or leaves play. 

[Cyberpunker]

Hey, I have another question about Sower of Temptation. My opponent has a Mogg Fanatic. I play the Sower. And he asks who I target. I then say I target Mogg Fanatic. He then says he can respond by sacrificing it.

I think that the ability goes on stack and if it resolves and he lets me pick a target, then it is too late for him to respond.

Does he have to sacrifice his mogg Fanatic before I declare a target or can he do so after?

[LotusHead]

When Sower of Temptation comes into play, gain control of target creature as long as Sower of Temptation remains in play.

When Sower comes into play, it's ability goes on the stack (and a target must be selected), then stack stuff happens.

In this case, you will likely have to suck up 1 damage from Mogg Fanatic, and Sower's Ability is countered on resolution due to lack of its stated target.

[Clariax]

Targets for a spell or ability are always announced when it goes on the stack, never when it resolves.

I think that the ability goes on stack and if it resolves and he lets me pick a target, then it is too late for him to respond.