If we get one, how would you want it done, which characters should be involved, etc?
If they go with character chapters again, then give Catwoman one if she returns. Neither MK Vs DC Universe's nor Injustice's story mode did her any favors.
I want Lobo to be part of it, even if he's strictly a cutscene character like Stryker and many others in MKX. His complete absence from Injustice's Story mode was predictable. Give him more than a small cameo. I'd prefer him to be playable and get his own chapter, but a worthwhile cameo could do, too.
Have generic NPCs to fight, just to avoid jobbing out playable characters as often as possible.
Finally, I wouldn't mind if the story mode was more like Street Fighter V's, with everyone, even the jobbers, being playable at least once.
