Does Emrakul, the Promised End trigger if the player casting it is being controlled?

Question

Say I cast Emrakul, the Promised End and am now controlling my opponent during their turn. As it turns out, they also have an Emarkul, the Promised End.

If I cast their Emrakul (while controlling them) does the effect trigger? This effect says:

When you cast this spell, you gain control of target opponent during that player's next turn. After that turn, that player takes an extra turn.

But it's unclear to me if I am casting this spell, or if opponent is.

Related: When controlling an opponent's turn after casting “Emrakul, the Promised End”, who is “target opponent”? which seems to indicate that if the effect triggers, then opponent gets to control me, but doesn't clarify if the effect triggers in the first place.

Answer 1

Emrakul's ability will work as normal when cast by a player controlled by another player.

When a player (A) is controlling another player (B), player A makes all of the game decisions for player B, but player B is still the one taking those actions. This is stated in a different way in rule 716.3:

Only control of the player changes. All objects are controlled by their normal controllers. A player who’s being controlled during their turn is still the active player.