Bloodstorm's Hidden Passive

[Deucalion]

The only other I know of is that Calvin sometimes counter-attacks, even without Block. Or at least, he used to if he doesn't now.

As for Shayd, I haven't seen any definitive proof of a hidden passive for her. She has 20 innate dodge so that could account for extra unusual strings of dodges (luck). Bloodstorm gets the same crazy dodge strings. I haven't noticed anything other than luck affecting her stuns, though I could be wrong.

I have seen Adamanti do the same thing, except it's a double counter.