Ok, so is there any difference in priority with his tornado or is it all the same?
AFAIK nobody has it figured out 100%. This thread: [
link] has relevant discussion, particular around pages 7 and 8, but I'm pretty sure a bunch of that is wrong, and the whole thread can be misleading.
My falliable understanding of the tornado is as follows.
The perception of priority is largely based on the interactions of hitboxes and hurtboxes. The MK deep inside the tornado is a hurtbox, and his hurtbox extends as tall as his swords which are at the top middle of the tornado. The hitbox is deceptive; it is wider than expected at the bottom of the tornado, and barely exists at the top (you can get right into the top orange corners without being hurt). You get hurt by the tornado if you let your hurtbox come into contact with its hitbox. If you're able to land a hitbox onto the MK hurtbox in his tornado, he gets hurt and the 'nado stops. So this is easier done from the top of the 'nado where he's exposed.
Priority mechanisms in general work different for grounded attacks than for aerial attacks. The tornado shows this by working differently in each case. When the tornado is on the ground, hitting its
hitbox with a strong attack can cause MK to abort the tornado, even without getting hurt. I think an attack needs to deal 10% or more than the tornado for this to happen, but I'm not sure. But note that the longer the tornado is out, the more damage it would do with each hit, so an attack has to be slightly stronger to interrupt the tornado the longer it's been out. In the air, the tornado cannot be interrupted unless you actually hit the MK inside the tornado. (This works on the ground too.)
Since the tornado is a rapidly multi-hitting attack, it doesn't easily lose "clash wars" against opponent attacks. Consider G&W's turtle vs. a MK tornado. Once the turtle hits the tornado's hitbox, both attacks clash. Once this happens, both G&W and MK are made invincible to
that hit of each attack (they are both multi-hit attacks). So if the turtle wants to knock MK out of the tornado, it has to wait until its next hit becomes active. (I think a turtle hits a total of 5 or 6 times total?) However, the tornado hits so rapidly, that it has many more chances to hurt G&W before the turtle can get close to MK's body. And also there is hitlag for every hit, so MK can SDI away from the turtle as he pleases. So even though the turtle is large enough to hit MK out of the tornado, it's difficult for the turtle to win because the tornado hits so quickly.
In the thread I linked, Niko_K theorizes ways that the tornado has more priority as its held longer. *shrug* There's room for tornado physics to be explained, so the above is just my own understanding.
Hope that helps!!! Sorry for the wall of text.... but yeah... priority is complicated o_O