Balzac's improvisation, as I see it, implies something musical, poetic. On the other hand, he's a philosopher, so he could also have developed suicidal thoughts.
And Goriot is out for obvious reasons.
In general, if we assume that the Hero is Romeo, then the killer is most likely Grande, because she broke his heart. If the Hero is Morgana or Oren (unlikely, but I think he could fit the role of a good-natured person, given Revan's twisted desire to make the newspaper descriptions as vague as possible), then Balzac could have been the one, if his "improvisation" is not musical but philosophical.
The other roles don't fit the newspaper descriptions in any way. In any case, we've lost a valuable player with a clearly useful role.

