#control changing effects

[magicjudge]

This question has killed me in multiple lifetimes. I cast Control Magic targetting my opponent's Light-Paws, Emperor's Voice. Do I tutor an aura from my deck onto Light-Paws?

This gets a bit fiddly, so bear with me here.

When Control Magic goes to resolve, the game changes immediately from Control Magic being on the stack and Light-Paws being under your opponent's control to Control Magic being on the battlefield and Light-Paws being under your control. There's no moment where Control Magic is in the battlefield and you don't control Light-Paws.

This means that Light-Paws was under your control at the moment that Control Magic entered the battlefield and so her ability will trigger because of it.

[magicjudge]

If a player who has control of another player's permanents in a multiplayer game, what determines if the other players get their stuff back when the stealing player loses the game?

It depends on how the cards entered the battlefield. If the owner of the card put it into play and then it was stolen with Mass Manipulation or the like, then it will go back to its owner as the control changing effect ends. If the player leaving the game put the card directly into play with something like Etali, then they're the default controller of the permanent and so it has no one to go back to and thus is just exiled.

[magicjudge]

Quick question on vehicles. Vehicle gets crewed, turns to creature. I use something to take control of target creature (not just till end of turn, permanent control). What happens when the creature reverts back to being just a vehicle?

It depends on how you're gaining control of the vehicle.

If you're using an aura like Control Magic, then it won't be legally enchanting the vehicle once it stops being a creature and so will fall off and return the vehicle to the other player's control.

If you're using a spell like Dominate, then you get to keep the Vehicle for as long as it's on the battlefield since the spell only cares that the target is a creature when the spell is cast and when it resolves. What happens to its types after that doesn't matter.

[magicjudge]

I control a Teferi's Veil. I Threaten a creature and attack with it. What exactly happens with that creature. I've gotten different answers from two judges.

You asked a question about phasing. I’m not surprised that you’ve gotten confused stares and different answers. :P

When the end of combat step begins, the delayed triggered ability from Teferi’s Veil triggers and phases out the creature when it resolves. When the cleanup step begins, the phased-out creature loses haste and returns to its owner’s control, still phased out. When your opponent’s turn begins, the phased out creature stays phased-out since it didn’t phase out under that player’s control. When your next turn begins, the phased-out creature will phase in (under its owner’s control) since it phased out under your control. It will still be tapped.

[magicjudge]

If you cast dominate on mutavault while it's a creature do you get to keep it when the turn ends?

Yes.

Dominate and other control changing effect don’t care what types the creature becomes after the spell resolves.