I don’t blame you.
Really, I’ve had my share of disappointment in the villain department too. I was honestly devastated by the ending of Crowley’s storyline in Supernatural. The characterization and outcome was so completely off in his final scene, that I flat-out refuse to accept it.
However, Markiplier does seem to have an overarching storyline he’s working with for his channel.
Think of it as like a “season” of a television show. A Date with Markiplier would be the beginning of the current season, reintroducing our villain that we thought long over and done with, as a stronger force against our hero. Which means that this new project could very well be our “season finale” of sorts, where all our patient waiting is satisfied with the building of the conflict to a climax that will carry us into a new season.
Aside from the rather odd timing of our “season” airing from February to October, it is roughly as long as an actual season on network television.
Also, there’s the fact that Mark’s bread and butter is still his Let’s Plays, and that’s something he can’t deviate too far from. The projects like this are a reward for the most loyal viewers who’ve been around for awhile and/or are willing to wait to be satisfied.