Just because the game makers deny something, that doesn't mean that they could've put what they denied into the video game subconsciously... however, I don't think this is the case with Serge/Janus, since, besides Kid's obsession with Serge, there's no evidence (and I've given up my theory of Serge's being found).
I think that Serge is actually the opposite of Janus... I think that Janus wouldn't want Schala to move on and find other people and selfishly would want her to only have feelings for him... I dunno if that made sense, but I get annoyed when my sister would rather spend her time while she's home with her fiance than me (she goes to college with him)
By the way, what happened to Wazuki in Home World? Fate no longer existed, so did Wazuki never turn into Lynx? I forget if he turned into Lynx before or after drowning Serge