I... can't even believe, that he trusts that nun chick. Sure she has a nice beetle bike (bike-beetle?), which in itself is awesome (Even if it looks lake something straight out of a Yu-Gi-Oh card.), but does that really make her trustworthy? I mean she homed right on to him and killed a monster knight, just to tell him, "I'm from a assassin guild and, congratulations, you are a winner! By the way, our most prized assassin planted her secret stuff into you, but that's totally not the reason I'm taking you with me." Of course, he can protect shit, if he is that gullible.
Also, that knight had a friend for life in that horse. Of course he is pissed.