True tips to get from casual to competitive in MKX.
Step One: Drop the franchise face Characters (this works in every Fighting Game) example: Scorpion, Sub Zero, Raiden, Liu Kang (They always get nerfed day one) in the same line of thinking, forget about character loyalism.
Step Two: look at the Characters with more move-sets and Special moves, better frame data on block and mobility; for example: Ermac,Cassie Cage, D'vorah, Jackie Briggs, Erron Black, Jhonny Cage, Kothal Khan, Mileena,Sonya Blade, Alien, Kitana,(secret top tier: Ferra Thor).
Step Three: of the mentioned good characters female hitbox characters (Alien Included) are outstandingly hard to get comboed
so in this game Female = top tier.( Side note: Ermac low crush most low attacks  with plus on block strings and unreactable 50/50s, Kothal Khan has plus on block strings, Erron black has a lot of unreactable 50/50s) etc. .
Step Four: specialize in one of those characters.
Step Five: Congratulations, your character turned you into a pro.