I've been thinking a lot with what the next Mortal Kombat could be like. The first and most important ideas I had was it obviously needs to evolve. I really enjoyed how the games progressed throughout the series and even with the reboot, I thought that was a very clever Terminator decision. But the previous game should be how we all get the classic MK out of our system and hope for something fresh and good in terms of story lines.
I would hate to see the next title end up a reboot of MK4. Why reboot entire series? Instead, maybe it could seem like the events of MK4 are unfolding only for a twist of something new.
As far as the storyline goes, I say sure to Shinnok's rise but I think something new should come of it. Possibly Shinnok's first stage of his invasion is Outworld. This could drive out the remnants of the old Empire. Reiko could lead a weaken army to reclaim Outworld during this event. So this could be a three sided battle between Earth Realm, Shinnok's Army and Reiko's Outworld forces. I then maybe some kind of twist during what seems like an altered MK4 occurs to really take us by surprise.
Killing off so many characters at the end of MK9 was a very bold decision but maybe it was for the best. This could be a good chance to flesh out character who had little development and appearance as well as add new characters. The only thing I could complain about is if they keep Scorpion around, they should have Sub-Zero there in some form or another. I thought of a concept where, regardless of how Kuai Liang resurrected, he comes back in more of a human form but uses the remains of his cybernetic form as make shift armor and weaponry of some sort, kinda like Cyrax's alternate in MKDA. This way we could have Sub-Zero but with a new take instead the same thing again and again. And maybe just have a more retro look as an alternate.
As of Scorpion, as popular as he is, wouldn't people want something fresh too? I don't know about gameplay but I saw some interesting fan art of him that I admired; he had a mask and cowl but was mostly shirtless with scorpions tattooed on his torso. The idea of straying away from the redundant ninja look was like fresh air to. Sub-Zero had a fascinating development ending with MKD, I was slightly disappointed to nit be able see where it went from there.
I thought of a concept where in this one, Sub-Zero and Scorpion once again confront one another and Sub-Zero informs how Quan Chi is deceiving them. Like MK4, Quan Chi appears only when Scorpion interrogates him, Quan Chi fails to cover his lies so he subdues him and offers Sub-Zero a chance to avenge Bi Han, for his own benefit, only Sub-Zero takes the high road of course. So instead, Quan Chi banishes the no longer ignorant Scorpion to the realm of Chaos till he can decide what to do with him. Then Quan Chi sends Noob to kill his brother to fill their ranks. More development between them could be done.
And with Scorpion trapped in the realm of Chaos, we can bring in Havok who pretends to mentor Scorpion and help him return to the tournament but really uses Scorpion to balance the war to keep the chaos going.
Even those Kabal was killed, maybe it might be cool to see him as one of Quan Chi's fighters and appear some what like he did in his ending now that he could be undead/corrupted.
If Shinnok ends up being the main antagonist then design the character like Kahn to make him an unplayable difficult boss. However, if there's any kind of twist then he could make a great playable villain.
So for a roster we could have:
Scorpion
Sub-Zero .. Of course
Raiden
Fujin
Kai
Quan Chi
Shinnok (maybe)
Havok
Skarlet
Sareena
Johnny Cage
Sonya Blade
Noob Saibot
Drahmin
More or less of the old but some new faces of course. Definitely focus on making things fresh before deciding to return old characters.
As far as gameplay, keep the 2D plane with 3D models of course. Maybe add interactables and transitions like Injustice. Return a more evolved X ray feature, fatalities, animalities, babalities of course. Maybe a kreate a fighter feature if it can be done right. More mini games would be bad because I loved chess and puzzle kombat. But more than anything bring back Konquest mode. I can seriously unplug my PS4 and plug in my PS2 to play Deception's Konquest mode right now. There was just something neat about free roaming the MK universe that I loved at the time. When there's already a ladder as the main mode, for a story mode, konquest would make things less repetitive.
As for a Krypt, making it more like MKDA would be nice. In MK9 there really wasn't anything new that wasn't already in the artbook. I found myself spending too much time looking at MKDA and MKD's content where MK9's felt like bare bones. All and all, these are things I'd like to see happen with the next installment.