With Alternator, I managed to easily solo 6/6 of "Waking the Beast" avatar quests with Sharpshot (use the steamjacket attachment). It seems Alternator gives a large amount of elemental resistance or magic evasion, because nukes are doing pretty low damage that can't be explained by the INT+70 (since these avatars are lower level, it's pretty easy for the puppet to completely resist all astral flows and nukes) and with combination with Steam Jacket, the 6 elementals and the avatar constantly spamming nukes do piddly damage and you can keep it alive indefinitely with repair/role reversal.
Unfortunately, I got Carbuncle Prime to 33% after killing all 6 of the avatars it spawned (easily), but the 5 carbies all had hate on me once they spawned, and instantly used Searing Light. I couldn't get my automaton to have hate on all 5 carbies quickly enough to survive, so it seems that part is impossible (unless there's some crazy strategy to survive the 800+ damage searing lights which you'll be bombarded with while attempting to get the puppet to tank all 5 again, in which case enlighten me)