What new content did Mystic make for 2.2?
Mystic came up with the base concepts for the tutorial's implementation, the "directionchar" character angle feature, and the autobrake, although all of these required implementation work from other people to take them from ideas to reality.
That's not to say that I'm unhappy he's gone. Far from it; I actively celebrated when I heard the news. But it's important not to let minor issues like how much he contributed to get in the way of the facts of his odious approach to community management, bigotry, and controlling nature. You can be the most profilic developer of the lot, but being impossible to work with will catch up with you eventually.