Abbot of keral keep

[Pardyr]

Do you have to use mana to play the exiled card Abbot of Kerala keep exiles?  Like if it exiles desolation twin. Do you have to pay it's casting cost or just boom there u go. 2 10/10 creatures on turn 2

[particle]

boom there u go. 2 10/10 creatures on turn 2

OP

[Pardyr]

All right. But that would be totally awesome if you didn't have to pay it.

[Pardyr]

If it is a land you exile and you already played a land. What happends to the exiled land?

[griffin131]

It stays in exile because you can only play one per turn.

[Pardyr]

Can an opponent put it in to your library with some of the new eldrazi's.

[Kaylesh]

New eldrazi abilities can {oblivion sower} put lands into play on your side that your opponent owns and you could bounce a land to your hand potentially

Would need a ruling there on if you can pick up an opponents land that is under your control.

I'm sorry, didn't quite catch what you're trying?
Bouncing always happens to owner's hand, so you couldn't pick up a land you don't own. I don't really get how it's related to exiling or {oblivion sower}, since that specifically checks exile for cards owned by a specific opponent.
It doesn't care how they were exiled, though, so if you cast Abbot, hit a land but can't play it, they can use sower to get it on their field.

[Kaylesh]

Just checking on the bounce effect putting into OWNERS hand

Because the sower could play a land and you can bounce stuff, I just didn't know where a land I control but don't own would go if I "return to hand" it

If you control, but don't own, you'll lose the permanent, as it'll go back to owners hand.
{boomerang} for example, or {evacuation}.