A user from another site has MKX and uses Jax -here are his notes about it.
Jax (Wrestler variation)
Gains Air Back Breaker
Automatic Gotcha Grab
Various Wrestler Strings
Ex Multi Slam (has armor) : Inputs have changed from MKX it is now: square, triangle, x, circle, then all 5 buttons, has to be well timed.
Multi Slam DBF 1 (2hits): triangle
Note: You can choose which side u want the grab to end on, on both versions of multi slam, also multi slam command grab has very short reach so u will have to be right up on ur opponent to get it.
Dash Punch (High): Still punishable on whiff like MK9
Dash Punch (Overhead) Hella Quick!, travels nice distance, and can be comboed in the corner, mid screen does not allow follow up, but hella unsafe on block
EX Dash P Overhead: Recovers more quickly on hit for follow up, dont know how safe it is on block
Jaxs MK9 F4: In MKX it is now his B4 (sweep) and can't be comboed into, but is still a hella good normal.
EX Gotcha Grab: Has armor and can be used as a AA, can be combo in the corner, and used as a wakeup.
Rising Knee BF 4 (DP) great AA move to catch jump ins
EX Rising Knee: Good wake up option
Air Back Breaker: Can still be linked from a JIK.
D3: Toned down from MK9, u can't spam this move anymore to try to dictate pressure, has a slight pause when connected.
D4: Decent reach, and nice option on footsies
Energy wave DB2: Can now be held down, but not dash cancelable
Ex Energy wave: Can be held down, but not dash cancelable, releases 2 shots, high and a mid
Note: Jaxes projectile is hella good this time around, much better then MK9
Ground Pound: Can no longer be canceled ( at least not in this variation) can still choose where u want it to hit
Wrestler variation strings: Jax has 2 special strings in this variation that allows for him to use his spine buster move from MK9 starts off mid and goes into a command throw which can be blocked.