Here's a Mai crossup shenanigan I kinda like, but most of the reward seems to be biased towards one side of it. Here's how it works:
s.CD > wait > MAX (raw activate), qcf+AC > d~u+AC (immediately, to wall behind opponent, hold for walldive attack)
This makes the 1st hit of the EX fan cross up. In order to block the fan, the opponent has to hold forward on their wakeup. Since the crossup timing happens when Mai performs the walldive immediately after the fan recovers, there's no time to wait and react to see if she does it -- you just have to hold forward on faith.
PROS:
+ Fan crosses up -- guaranteed to hit anybody who doesn't know about it yet
+ Sequence starts a combo if timed properly
+ EX walldive attack is completely safe on block (plus)
+ Crossup is unreactable, you just have to hold forward and assume Mai will commit to the crossup by immediately walldiving. If you start at back and try to switch to forward on reaction to the walldive, you will get hit and Mai gets the combo because it's autopilot.
CONS:
- Safe if fan is blocked, but you go back to neutral because opponent can escape 2nd hit and Mai's not close enough to punish jump back/backdash without Climax Art (expensive)
- There's a gap between the fan and the walldive if the opponent crouch blocks the fan. Otherwise, the fan -> walldive is a true blockstring, because the 1st hit of the EX walldive gets stand blocked.
- If you don't walldive off the fan to make the fan fake-crossup (opponent holds forward and takes the fan to the face), there's no way to combo without immediate YOLO Climax Art (I think, need to double-check). The fan almost certainly won't protect a blocked Climax from punishment, particularly if the opponent guard-cancel rolls.
- Doesn't work against cornered opponent (but that's okay, because the opponent is cornered and there's other, higher-reward stuff available)
- Universally punishable by two methods: (1) guard-cancel roll the fan's 1st hit fiorward, then whiff punish Mai's walldive, or (2) reversal roll the fan, which is legitimately difficult. If you're playing a character such as Mai who has an invulnerable super that hits above her, you might be able to super thru the meaty fan to hit Mai as she flies overhead, but the rapid-fire crossup can make buffering the command legitimately difficult.
- Does not loop the setup back into itself from what I can tell; maybe if you end with super for a hard knockdown, but that's expensive since you have to burn another bar right after to reactivate.
tl;dr if the opponent gets hit by the crossup fan, you get a combo. If the opponent blocks the crossup fan, you're safe if the opponent does not guard-cancel roll the fan (disclaimer: so long as you block the fan, that's not hard). But if you make the fan fake crossup by not doing the walldive or doing a delayed walldive (or other action), you can't do a true combo on hit, and there are way more holes to escape through. So it's a one-sided shenanigan, but it'll almost certainly work 1-2 times before the opponent learns how it works, lol.