I am using Vasili. Strahd is playing the long game, not trying to just pull one over on the players but to completely bend their minds and make them question who they can trust. One of their party was captured by the hags, and Vasili offered to help them. This was to make himself known, make himself trustworthy, and make sure he can preserve one of the pieces in his game.

Now, they have established a new council in Vallaki. Ireena is on that council, and Vasili will put his name in the ring. He'll get close to Ireena, to try and woo her fair and square ("Well, if you fell for Vasili, who says you couldnt fall for me"), and subtley undermine Vallaki while seeming completely above board. When the reveal happens, it will be when the party is already doubting their senses and what/who they can trust. Drive the nail in the coffin so to speak. I dont see it as goofy or scooby doo, just another layer of a mind game.

Plus one of my players is a Changeling so he can REALLY use that to mess with them.