Here is a small sample of Mai's crouching heavy normals canceled to Musasabi (down~charge~up+P) then j2B.
As implied in the Mai tutorial THIS CAN BE A BLOCK STRING if you are quick enough with the j2B input after ground Musasabi. The j2B is still going to be an overhead (and cr.D can be whiff cancelled in to her ground Musasabi or other special moves as well).
j2B used in front of the opponent is plus frames on block. Most of Mai's light normals, close heavy normals and her cr.C will come out quick enough to keep the pressure going.
(cr.C/cr.D, ground Musasabi > instant j2B, (land) cr.C...
you can repeat this to confuse or continue on with block strings... or she can pressure the opponent with crouching light normals, stand A... and tick throws/running throws - low/throw games are general dangerous in this game.
https://www.youtube.com/watch?v=AsSrfNQmulkNote that EX Iori can not mash DP or normals between Mai's crouching heavy normals into ground Musasabi instant j2B.