Great! Charon's just going to be zoned in on figuring out what the heck happened, fixing it if it's something medical/physical he can fix, and getting back to business as usual. So any insight from people who've known the Tank for a while should be hugely helpful. That should be some fun backstory for you to play with for those two characters, neat. : )
My second, an Echo with probability manipulation, (just tapped) has been around for seven or eight years. She's kind of in the same category of sunshine/sweet and possibly a touch naive, with lots of good heart. So I'd imagine they'd get along well.