The input for the first part (just in case there's confusion) is j2, 32 xx MB RLG, d2 xx teeth, j2, teeth, 213 -> teeth, MB f3 or crossup j2.
The timing for the j2 is a little strict, but you'll get it down with time. I do it by just holding up after tossing the teeth before it and tapping 2 as soon as I see myself leave the ground. It's pretty engrained in my muscle memory at this point, so I generally don't drop it. The 213 timing is also very strict to produce a truly super hard KD; you have to wait a moment before inputing it, otherwise they tend to fall faster and stand up quicker, not letting you get the setup properly. The MB f3 is a little tricky too. My trick there is either hitting it as the teeth touch the ground, or hitting it while the teeth are falling and holding it slightly. Doing one of these two things is important to make it as near unblockable as it can be. Otherwise, it's pretty easily blocked by your opponent like an earthshaker, especially if they have MU experience. Hope this helps.
