There's a scene where Agatha's creatures from the recharged Castle are swarming the fleet, and Klaus is basically defending the control center of his flying city. He's murdering countless amounts of these things (sometimes by 'grab metal face and crush it with his bare hand') while assessing reports from underlings, considering the situation tactically, and issuing complex commands.
One more spice to add to the Klaus pot.
Edit: Haha, it continues. Klaus shows up solo to Mechanicsburg after the Castle gets charged up. A highly-confident Jäger general loses her **** at first sight of him and screams at her ARMY to attack him, all at once (this is very un-Jäger, especially of Generals who casually beat up small armies themselves).
Clearly, she considers him the worst threat around when he's standing there, all alone. This is a general who never lost her composure the entire time she was helping defend Mechanicsburg against an army of Clanks and monsters while the Castle was limping along on the dregs of its power. Presentation-wise, this rather supports the idea that Klaus, alone, is considered by the Jägers easily dangerous enough to require ALL of them to attack. Yeesh.
She attacks Klaus, herself, and he leisurely leans out of the way of her attack, avoiding it completely while barely moving.
We don't see any more of the fight, because Klaus surrenders. He has A Plan™, clearly.