Ok so today I went into the lab to explore Mileenas AA options and while some of this stuff is known I would like to share. Since I feel stopping and preventing bad jump-ins should be a refined aspect of any fighting game players arsenal. Mind you these are what I found to be general go-to's. Some of it may not work in certain match ups while other things, such as f4 low profiling and punishing Kung Laos spaced out jf2, are matchup specific and not worth mentioning.
2 - 8 frame start up, hits as a high, and good AA hitbox. Good for catching crossovers or when the opponent delays their jump in attack. To maximize damage potential follow up with f23xx roll into your ender of choice or you can another 2, b12xx roll for some extra damage.
1 - works just like 2 however I prefer 2 due it's faster startup and extra active frame. I'm only putting this here due to the fact it has slightly longer range.
D1 - 9 frame start up. Situational AA, for example an opponent is trying to cross you over to start their pressure and does early jump in punches, d1 will low profile and hit them in most circumstances. This can also work as an unorthodox low profile move due to a very peculiar hurt box that almost seems to push the opponent away in some instances. Same follow up mentioned above applies after a successful AA.
D3 - the beauty in this move is the ability to low profile and it's quick recovery. Because of this it's possible to throw out d3 and punish your opponents landing frames with either d2, 21, or raw roll. The window for a successful follow up seems to be inputting d3 just as the opponent is coming out of the apex of their jump. This is a relatively advanced yomi tactic so be mindful of what you're committing to. If you want to play it safe you can always try to simply establish your own pressure game instead punishing.
D2 - no explanation here. Great for stopping jump ins due to its speed (8 frames) and hitbox. Become familiar with the deadzones (areas where it's risky to throw out if the opponent empty jumps or can whiff entirely) and use it. Now here's something you guys may not know, if your uppercut trades against jump in punches Mileena will stay grounded. Train yourself to see this and input low sai for 18%. If you're close to or in the corner you can ball roll, walk forward, njp b212+4 for 32% or go for a hard knockdown.
Roll/EX Roll - 8 frame startup, covers 3/4 of a full screen, incredibly low profile hurtbox. If done too early your roll will whiff but this is not bad thing seeing as it resets the neutral game. Be wary, the viability of this depends on the matchup. Characters with low reaching jump ins such as Jason and Kung Lao can blow this option up. However ex roll can work well against attacks like these and as a AA in general. This can also work well to stop crossovers. Typical roll follow ups work such as b34xx sai, but in some cases Mileena will travel further than normal. You can either immediately dash in, njp, b212+4 for a setup and 24% or jfkxx air sai, rc b121+4 for 26%.
U3 - 11 frame start up that can be MB'd into more damage. Does 13% by itself. If you choose to MB midscreen you can do rc, 2, b12/f23xx roll, b212+4 for 37% or end with 21u4 for a hard knockdown. In the corner after roll you can walk forward, d2, 21u4 for 40%. Good tool to stop crossovers and poorly spaced jump ins.
B3 - 15 frame start up which isn't terribly slow. Used to stop forward jumps, the trade off for using this over uppercut is the damage potential, and speed. Buffering telekick into this allows you to combo into air sai, rc f23xxroll then end with a hard knockdown or sadistic ways. For 30% and 35% respectively.
B1 - good situational AA due to its hitbox and speed. Useful for stopping jump ins that are outside of your 2/d2/b3 range and where roll is risky. You can buffer sai for 11%.
Neutral Jump Punch - 6 frame startup, 15 active frames. Decent air-to-air. Has slightly further range than d3. Can lead to 35% if you follow up with fjkxx telekick, air sai, f3xx roll, b212+4. If you're opponent is too low and you don't think f3xx roll will hit you can do roll instead for 33%.
Forward/Back Jump 4 - 8 frame startup, 9 active frames. Slightly better than jump 3 due to it having a more forward angled hitbox and more active frames, however both can be used interchangeably. Can lead to good damage, 30-35%, by canceling with telekick, air sai, f3xxroll, into ender of your choice. Again do raw roll if the opponent seems too low to be able to catch with f3.
Forward/Back Jump 1 - 10 frame startup. A good air-to-air with more vertical space control than jump 4. Same follow ups as above apply for 28-33%.
This next part is for the newer players and to help me gain understanding, seeing as I'm an SF player in transition, so there's a lot to learn! As I'm coming to understand against crossovers, mind you I am relatively new to MK, if the opponent tries to start their pressure with a crossover punch this is where you'll see buttons like d1 and 2 shine. Because it forces your opponent to guess early, in which you use d1, or late, in which you use 2, to counter your button presses. However if the opponent catches onto this or knows this tactic they'll begin to use early crossover kick to snub your AA's entirely. The penalty for this is if they guess wrong and you block, they relinquish pressure. This forces the opponent to either respect you by blocking, jumping again to catch a slow normal (you can answer with an AA in this instance), or armor through your attempt to re-establish pressure.
As I said I'm learning so someone correct me if I'm understanding the meta wrong.