What a pretentious jerk...
Anyway...Zeta Savage is unkillable for a great many teams, literally wiping out entire squads by himself. You can't control when crits hit. Hell, you can't build an effective squad without crits, so you shoot yourself in the foot when they do hit. He heals on every move and takes moves every one or two hits you get. On top of that, he's gaining massive damage boosts with instakill if your health falls. Buff and heal immunity are the usual suspects for dealing with the heal spam, but he loses them and then heals. If he's alone, Zader loses his advantage. Fett's Execute is good, but his health is so high that it's hard to finish him with it.
Every other Zeta has a vulnerability. They went too far with Savage.