Discovered a few days ago that while initiating the spinpunch combo, press A and B simultaneously after pressing A twice. This will allow Shrek to move quite a distance forwards and the punch itself is also quite fast (he only spins once) in addition of being able to break a shield, and I feel it has overall more utility than his normal one. I have yet to test it properly however, as I don't know if the hitboxes are changed.
Nah, I slept through the comet that wiped out the unicorns!
This is his AAO, yeah? Definitely one of the best looking ogrements. Big swirly blue glow, like an oven hob. I think it's just as it looks: a shield-breaking variant of the normal spin, complete with the standard spin hitbox.