Modern

[5/9 Turtle]

I'm not any good at rulings so ill leave the rulings to keyeto

[Birdbrain]

He had a {galvanic alchemist} and {door keeper} and {axebane guardian} already in play. He tried to pair the first alchemist to the doorkeeper when the second entered the battlefield

[5/9 Turtle]

Yeah he wouldn't have been able to do that, it's logical to me

[Keyeto]

He had a {galvanic alchemist} and {door keeper} and {axebane guardian} already in play. He tried to pair the first alchemist to the doorkeeper when the second entered the battlefield

Alright then, thanks for the breakdown. The first alchemist would not be able to be paired to the door keeper. The second one can pair to whatever it wants, but the first one had its chance. The only way a non-paired soulbond creature (the first alchemist in thjs case) can pair with another creature once its on the battlefield, is another creature entering the battlefield, in which they can pair with THAT creature.

Here's a ruling, to help clear things up a bit:

702.93a Soulbond is a keyword that represents two triggered abilities. "Soulbond" means "When this creature enters the battlefield, if you control both this creature and another creature and both are unpaired, you may pair this creature with another unpaired creature you control for as long as both remain creatures on the battlefield under your control" and "Whenever another creature enters the battlefield under your control, if you control both that creature and this one and both are unpaired, you may pair that creature with this creature for as long as both remain creatures on the battlefield under your control."

The part relevant to this situation has been bolded.

[Birdbrain]

Draw

{ancient ziggurat}

Attack with everything

[Birdbrain]

He's gone...

And I think he modified that post

Never mind.