May be he didn't play his role in DD and BD but I fully support this suggestion - he could be some kind of more active "mascot", more active than that White Cat. Like, for example... ugh, I don't know, like Riddler in new Batman series or Patch form Demon/Dark souls? Something in the same concept.
....and I didn't mean DOS only, I was talking about DC too (but I guess it is too late to add him into almost finished game).
