Lucifer said:
Plus we know Kruppe has, at the very least, an immense amount of skill with whatever it is he uses. He's, also, either very powerful, or is now backed by K'rul, as he does turn away the power of Brood's hammer and anger without breaking a sweat (except of course the one that he's purpetually mopping up
). And to me he seemed very calm and confident that he could.

We haven't seen Kruppe use any real power yet, he's a low level thief and carlatan, as far as we've seen he merely has some parlour tricks, perhaps derived from Mocra, at his disposal: Stealing cakes, muddying that don juans mind, etc. Sorry/Cot didn't sense any real power in him.
The rest is most certainly K'rulls gifts. ottataral left him powerless in GotM, and no power any fat mage can dish out with was going to save kruppe from Broods hammer swung in rage.
What makes Kruppe so awesome is the same thing that makes us enjoy Tehol, their just mortal men with enough brains and brass to confound the gods.