Yeah, your choices do matter, I believe.

Hence, it was Paine who Enzo asked to save Rei.  While this arc would try to focus on Drakus, it's by no means something to force him to become a hero.  If Drakus does choose to be a hero, something will happen which will push the story in another direction.  If Paine goes in to do the hero work, the Witch will do something else.  If Rei gets out alone, the story changes again :D

So, yeah, just do what your character would do, and the story will flow nonetheless.  If something important comes up, I'll be PMing you so that we can discuss how you want the story will flow.

In this case, depending on who does what to save Rei (which is the focal point for this scene), I'll be pming the needed people :D