Mutavault and combat

[InfinitiveDivinity]

He needs to cast cryptic during the "Beginning of Combat Step".
Once you move onto "Declare Attackers Step", your creatures will be attacking.
So yes, there is a window, if he tapped your creatures during "beginning" that you can activate Vault during "declare" and make it attack

Im aware, I just wasn't sure if there was another instance of priority, which of course there would be, after resolution. Yeah, if he just passed priority I could kill him with my board.

I must point out something remillo has missed. If you move to the declare attackers step, you cannot then activate {mutavault}. The first action taken in the declare attackers step is declaring attackers, not the active player receiving priority. If you want your creature to attack, he must be a creature before you have moved to declare attackers step.

Given the circumstances, that's not entirely relevant, since at least in my mind, the only reason Vailt would be activated at all would be if Cryptic is cast.  Basically having it as insurance to have at least one creature attacking.  However, you are correct.

I just meant that people had posted incorrect things and you didn't correct them. It wasn't relevant to the OP. Thanks for always being on top of it, sir!

I actually had already addressed that situation by saying I was presenting lethal, and survival meant a Cryptic. I even mentioned the exchange of okays during priority passing between Main Phase 1, Combat Declaration and Declare Attackers.