Ultimate Sonic Boss Fight

Ok, the final bosses of these games:

Sonic Adventure
Sonic Adventure 2
Sonic Heroes
Shadow the Hedgehog

That means:
Chaos 7 v.s. Final Hazard v.s. Metal Madness v.s. Devil Doom

Who is the last one standing (or flying or floating or whatever the hell they do)?

Perfect Chaos is invincible because of the Chaos Emeralds.
FinalHazard was killed.
Metal Overlord can only be harmed by team blast.
Devil Doom can only be harmed by hitting is eye.

I'm not so sure that Chaos 7 is invincible, even with the CE's. Just to be sure, let's take him out of this fight.

Between Devil Doom and Metal Overlord

Well, I think Black Doom is the most powerful of all. The second best is the Metal Overlord as he (it?) has the powers of Caos. I'm not sure between Chaos and Finalhazard. Chaos is the god of destruction, but Finalhazard was about to destroy the entire world, where Chaos could only destroy the Station Square. The only downside of Finalhazard is that he is artificial.