Minions

I wonder if at ANY time in the foreseeable future we MIGHT get a Sephiroth AND a Zack
Fair minion ?

It's not out of the question, as we have numerous minions based on other Final Fantasy characters, but we have no insight into when or where they may implement them.

I would say it's a very slim chance. So far we seem to have villain minions only if they are in game as bosses (Exdeath, Kefka, Cloud of Darkness) and hero/main characters seem to usually be pre-order bonus, fanfest, or collector's editions when the theme matches the expansion.