Square-Enix has said they're thinking about adding new battlefields using the HKCs/KCrests already. Could the KCs ones be soloable Pulling the Strings style BCNMs, hopefully with subjobs and no level cap, and reward AF3+1 seals? I think that would be pretty awesome. Could the HKCs be group battles that drop +2 items? That also would be kind of rad.
Get on it, Square-Enix!