This is perhaps a dialect/regional thing, but I'll share it because it's a bit silly, as such games usually are. Also, I don't know if it would apply to this particular game, or if other English speakers around the world would use this, or perhaps I'm just showing my age . . .
Here in some parts of the UK, for games like hide and seek, or tig (aka tag), where you have one person who controls the flow of the game, and then it's time for somebody else to take their turn in this role, we would say "You're it".
It's my turn, I'll be it!
No, it's his turn, he can be it
No! Can I be it?