Playing the first quest and had a question about using his ability to cancel effects of a card and reveal new one while shuffling old one back in.

How does this work?

A) cancel only when Revealed part

B) cancel all text on a treachery card ( ie - doomed, surge) as well as when revealed but not enemies and locations

C) cancel as per B and also cancel an enemy ( ie - shuffle a black rider back in) and location cards

It isn't clear to me. Seems like if I can just reveal a card and treat it as blank (disregarding it entirely no matter if treachery, location, or enemy ) this is quite powerful.

C) cancel everything. EVERYTHING !

you can even cancel burden.

Don't forget to replace it!

It is powerful. It's the One frickin' Ring!!

It is pretty dang powerful but I've often drawn another copy of the same card I cancelled when using it or once or twice an even worse card. It also only shuffles the card rather than discarding it meaning if the encounter deck is low on cards it only provides a temporary respite.