Actually, now that I think about it, this glitch might not be faster in 100% since you neon jump to the left wall before calling Zero and are subsequently nowhere near a green charge upon Mosquitus' room, which allows you to bait Mosquitus much further to the right while waiting for your charge.
Here's some
disassembly of the Mosquitus descent behavior that FractalFusion did, since it may be useful for the 100% run Glitchman is working on.
The way it works is, every 4 frames, Mosquitus will poll 3 RNG values. Presumably, 2 of them are for the smoke cloud he creates from being damaged, and one is to determine his direction. Depending on when you kill Mosquitus relative to the global timer, these two events may or may not coincide on the same frames. If they do, the values relevant to his choice of direction are the current value the frame after 4 values are polled, and if they don't, the current value the frame after 2 values are polled. Since the RNG also increments once every frame, this means 7 values will be polled every 4 frames.
As such, this text document has the RNG sequence divided up into 7 columns, so any Mosquitus descent pattern would start on a given value then go down that column for around 30 values(depending on how optimal the pattern is). RNG values with nothing next to them cause Mosquitus to fly towards Zero, and values with letters next to them represent one of eight 45° angles.
This table doesn't account for whether or not Mosquitus will attempt to grab Zero at the very start of the fight, which also needs to happen, so some of these patterns that look good may not be viable. But since you dump the second preliminary buster shot off screen while falling back to the ground, you can potentially drag it off screen quicker or slower to advance RNG at a slightly different rate in between the getting grabbed and the descent(or delay your saber slash).
It turns out that the air dash slash causes the least hit lag of all the slashes, and even though it deals slightly less damage than the standard combo slashes, it still has a much lower ratio of hit lag caused per damage dealt. So the first 3 phases of each boss fight should use air dash exclusively in order to delay the dynamic difficulty timer as little as possible, unless other slashes are needed to make certain transition thresholds in time.
During the final phase, it seems that aerial DPS beats ground DPS by a significant margin. Even though the sliding slash is much more powerful than any of the air slashes, it causes far too much hit lag and has far too long of an animation to be useful in situations where you can hit bosses in the air.
Link to video
This fight improves upon the published run's Blue Monk fight by 16-17 seconds. By canceling an air dash with a normal slash while close enough to the ground, landing will cancel the slash and allow you to start a new series of air dashes immediately after. This doesn't work on the 3rd air dash, so you can only do maximum of 2 dashes at a time this way. It might be worth using Misty Slash to interrupt his desperation attack in the final phase if it can prevent his final jump, but I'll have to look into that later.
Everything leading up to and including Wanyudo should be pretty straight forward. There's a different route with different shrine teleports that RTAers use leading up to Yukinojyo and the mountain god fights. I'm not yet sure if the route is actually faster or if it's just used to stock up on more smoke bombs and grab the pheasant hot pot recipe(neither of which would be worth taking a considerable detour for in a TAS I think).