Is it just me, or am I the only guy on this site who actually liked the "New Generation" of Earthrealm fighters (Cassie, Jacqui, Takeda and Kung Jin)? Granted, it's mostly for the snappy one-liners they fire off during pre-match dialogue (look up "Cassie intros", "Jacqui intros", etc. on YouTube to see what I mean), but I also don't think their stories are really BAD - sure, they're not exactly surprising or groundbreaking, but they work just fine for me.
That being said though, I REALLY want to have at least one chapter in the next game devoted to Erron Black (especially with how his ending showed he was basically granted eternal youth by Shang Tsung 150 years ago, likely making him a real Wild West-era cowboy), and I DO hope the next story allows for some non-linear storytelling (I think that MKX was originally supposed to have branching paths, or something like that).
Hopefully, if they take time away from the microtransaction crap in this game, they'll have more time to actually focus on the story mode for the next time around