So, this game is essentially single-player as in you play as a single character (from what I know I think you're the succubus controlling the body of the mage?). I don't think you're supposed to play this game with 2 players however there's a collaborative(? is that the right word) aspect of the game involving the servants in the throne room being able to be sent out to other players's respective throne rooms. If you do mean the mage and succubus separately I don't think you can play them separately due to the fact that currently the mage only gives feedback and acts kinda like a ... trophy wife? (I'm definitely using the wrong words here)
No, you cannot play 2 player as the Mage is not a separate player
(If that's what you mean)