I must say that I'm excited about the Mind Swap Magic premise. I enjoy swapping decks with my friends and giving their strategy a whirl. Doing so midgame could be pretty sweet. Of course, being the sometime griefer that I am, I'd be tempted to build a terrible deck incapable of winning on its own. You know, along the lines of decks built around that enchantment (which name I cannot remember) that essentially has players switch libraries by exile-drawing cards. I was going to build a deck with that and walls, but decided it would only win once per opponent, if I was lucky.Anyway, a non-griefer strategy with such rules could be a lot of fun.
Why would you build a deck specifically for this format? I always like to play different formats with the same decks I always use.
Me and my group play a multi-player variant called knight and traitors. its has become what we play almost exclusively. Its kinda like BANG but the rules are a little different. most notably the knights and the king are not on a team and the king wins when he reaches his 15th turn. I could post the rules if anyone is interested in playing it.