I don't know that Xorn is all that great. In both of our games he was situated perfectly. Once he takes damage he's a challenge, do you heal him or use him on his current click?

In an X-team, where he can be healed up easily, he's great. But if you'll notice, I often didn't use him at all (with the teleporter and Jean in play, he wasn't needed).

He's a great piece but not one that can't be dealt with.

I'll concede the point for now. We've both played him and won't be seeing him again in one of these for a good long while now. I still think he's virtually impossible to take out in this format game, if the player doesn't want him to be.