MX

MX is a particularly ruthless and demented entity who will go to any length to claim as many souls as possible in order to integrate them into the game and make them his playmates for all eternity. Having existed since the beginning of time, all of his pent-up murderous sadism has been waiting billions of years to be unleashed on unsuspecting humans for his own amusement. He appears to have no remorse for his actions, dismissing his child victims' innocence and claiming that it won't get them far, confirming that he doesn't care about their age as long as he gets to torture and murder them.

He is also extremely intelligent and manipulative, having duped Lucas into believing he was trustworthy in order to gain an advantage over the child and eventually lead to his death. He's also astute enough to ensure that his victims have no way of retaliating against him, as evidenced by his removal of all powerups from World 1-1 and possibly the rest of the game, which may indicate a paranoid side to him if he's willing to remove anything from the vanilla game that can be used against him.

Despite his wicked nature, MX's general demeanor is that of a relaxed, calm, and collected entity that can genuinely be polite to people when he wants to be and can strike up genuine friendships with people, particularly those who share common interests with him, such as Lord X, most likely due to inheriting some of Mario's personality traits, particularly his friendly nature