Personally, I hope MKX introduces an entirely new big baddy that outclasses even the fallen elder god, Shinnok. For example, the King of the NetherRealm. He could be a character with a stature similar to that of satan. He could also be a looming sinister presence that influences the course of events throughout the game. His full reveal as the new Big Baddy would come in MKXI, kinda like how the Dragon King was hinted at in MKDA and revealed in MKD. Here's my dream lineup for MKX boss battles. What is yours?

Sub boss: Shinnok
-Phase 1: Super powered human form (non-playable)
-Phase 2: His monster form from MKSZ Mythologies (non-playable)
Note: Only normal powered human Shinnok should be playable

Final boss: The NetherRealm King aka Satan (non-playable)