I think I'm going to go with the idea of the Mind Stealer needing X successful abductions to win the game. A stolen role is added to their Collection, which will include 3 random roles at the start of the game. Should the Mind Stealer be killed, all roles in their Collection will be randomly distributed to players who have a Vanilla Role of some sort. So, vanilla town, vanilla dopp, maybe Survivor Alien?
Survivor Aliens getting a role would make things interesting. Their win-con would stay the same, but they'd suddenly have some interesting and unexpected role to possibly help them fulfill it.
One thought on the Mind Stealer's win-con: What if they needed to steal X 'points' worth of roles, and got tech? That way they could take some investigative tech to try and bag better roles (Wardens, Advanced Dopps, stuff like that), or Defensive Tech to try and say alive long enough to grab enough randomly selected roles? It would certainly make the role a little more interesting to play, although it'd be slightly harder to balance. Still, I could pull the points off of my weights spreadsheet that the perl script uses to generate the set-up, so it wouldn't be too bad.
Thoughts?
It's survivor with a twist. More power. Downside is that it collects powers that it doesn't want to use, since it has to abduct, unless it grabs a day power role. So really is just an ICM with the ability to give (most likely Dopp) power rules on death. In that sense, it's probably more likely to be killed if found out. On the other hand, I would hate for the game to be broken because a Dopp got her hands on a vigilante role.
Maybe it's like Xeno, but more powerful and potentially game breaking. I feel like its a 5.5/10. It doesn't feel like it adds more than the mind wiping, but that generally feels anti fun. It wouldn't ruin the game, but it wouldn't add a whole lot.
But that's, like, my opinion, man.