Killian wins IMO. Ghost was cool and all, but she can still be tagged. And I doubt she could put Killian down before getting roasted by his heat. The guy survived being inside an Iron Man suit as the thing blew up, and had a healing factor that allowed him to regrow his entire forearm in the space of like a minute or two IIRC. Plus, he was physically strong enough to contend with the suits and fast enough to casually dodge pointblank repulsor fire. Oh, and he can breathe fire.