I was rethinking reappear after down-b. I criticized the option multiple times because of its huge reappearing lag. Lets say your opponent shields. If you reappear in front of them, they should be able to punish you, the reappearing animation is just so long... Reappearing over the opponent is also kind of senseless because you don't go up that much and reappearing is 18 frames, plus startup from an aerial... Every character has options punishing it.
If you were in the air before, it is also highly questionable because you force yourself into a bad landing, you can probably escape but there is just a little chance you will ever profit from it. Most try the option with the aim to do an aerial while falling then, but MK's aerials on shield can't be just played out raw. And therefore you need the ability to maneuvre before and without jumps it doesn't work.
If you reappear behind them on the other hand, half the cast isn't really able to punish consistently. Then, you are at least in the realm of mindgames and it is not an outright bad option. The main mindgame options are in this situation:
f-tilt as quickest hit, against startups on moves as will as jumpsquat if they want to punish with bair.
Shield if they are already putting a move out, probably it is nothing more than a panic reaction and therefore bad on shield.
Grab if they still wait in their shield, it also beats some other options including slow punishes where there are still in startups.
Their options are mostly WD away from your new location (will probably result in neutral game), a punih like a bair, some characters have alternatives and keep shielding. This mindgame should be favourable for you.
I still think down-b reappearing is not that good because any hitbox during your invisibility will hit you and if they predict the option the punish can be big. One main method can be to wait a very short time if it is an IDCape, if not, doing a SHFFL nair to eliminate the crossup reappear and then shielding again if you still didn't hit do be safe against other reappearing forms. Clearly, you can now do tricks like down-b -> wait a little bit -> c-stick cancel once they naired, but overall the mindgame should be slightly favourable for them, if they are aware of both players' options. If they fall for the crossup reappear though and fight it the wrong way, you will be able to get clear down-b hits again. On the longrun they should be able to put a huge question mark on your down-b usage in neutral. But as long as they aren't prepared, this is useful.
