[quote=@BilboTheGreat]
So if and when the creature that actually put on the mark shows up, I would play them?

Sorry if I seem like an idiot, just confused xD
[/quote]

Yes, whatever creature serves as your character's "antagonist" is up to you. And no problem, this is probably going to be a confusing concept to a lot of people because the general formula has the GM controlling all the bad guys that challenge the heroes.