A bit late to the party, but the fellow with Crystal (identified already) is Lee Reherman. Former American Gladiator and actor recently in Star Trek Into Darkness. The two of them are indeed in FireFall gear as Mourningstar and Typhon.
Don't know if you've read my previous comment here, but the other lady on this pic is She's a professional cosplayer, maybe you wanna check out her gallery? I don't know who her partner here is, though
Hope this was helpful - and awesome group shot, btw!