Hayato’s Engetsu (shockwave) has some interesting properties…
The first: It’s fast, but the first hit is a melee hit… a downward slash of his sword. After that, the wave comes out. The wave cancels projectiles (HSF), ignores beams, and keeps going to the end of the screen. It does more damage the closer you are to the center of the spikes, I believe… it does not reach extremely high, so it’s best to combo it, or call it in response to or during an opponent’s projectile super (i.e. HSF, Legion, etc.)
If you whiff, Hayato’s end pose lasts long enough to be AHVB’d. Don’t toss it out.
It can be DHC’d out of after the first hit of the wave, and continues travelling until its last normal hit, making it good for DHCs.
Finally, the (almost useless) glitch. If Hayato whiffs the Engetsu while the opponent is crossing him up, so long as the wave has already started travelling, it will turn around when he gets hit. Most of the time, it hits the opponent, or prevents the combo. But it’s dumb as hell to whiff the Engetsu, so you won’t see it much.
Engetsu does good damage when successfully comboed. It suffers a lot from Damage reduction, but makes up for it by being a good DHC. 50% on a good combo.
The Best Engetsu Combos seem to happen off the first hit of the shiden (plenty of time). It combos after the second hit as well, but certain notable characters cough Sentinel, Dr. Doom cough fall out of it, which is more than inconvenient when they roll behind you halfway through. Does more damage off the second hit, but it’s guaranteed not to get you killed off the first. Your choice.
Rasetsu Zan, Hayato’s other super, is also a good DHC, and seems to suffer less from Damage reduction. But that may just be me. It’s more difficult to combo, though, because it has horrific startup time. I’m just beginning to appreciate it’s ability to catch assists, and combo into beams, however.