A situation came up in a game the other day where I did not know what should happen.

First question:

Let's say a bantha is moving next to a nexu. First, it moves such that their diagonals are touching. Next it moves one square farther so they now share an edge.

Can the nexu play Parting Blow there?

The wording is a little weird, because the bantha still occupies the space. It has not technically exited any spaces adjacent ot the nexu. However, a piece of the bantha exited a space and moved to another adjacent space. Is that sufficient to play Parting Blow?

The crux of this question is: When a large figure moves, does it exit every space and then enter every space it is moving from/to?

Second question:

Let's say the nexu waits until the bantha is completely over top of the nexu. The bantha tries to move one more space. Can the nexu now play Parting Blow?

If he can, then how does the attack work? Does the bantha have to stop moving?

From what I could find in the rules, I didn't see anything that said the bantha had to actually stop his movement to be attacked here.

The rule about not being able to have an action be interrupted while over top of another figure doesn't apply, because the bantha is not in the middle of an action.

If the bantha does have to stop moving, this could potentially push the nexu to a square where he can no longer attack the bantha (due to other figures nearby).

Does the Parting Blow attack no longer occur?

Does the nexu still get stunned?

Finally, what if this nexu has Punishing Strike and applies Stun instead of Bleed? I assume now the bantha does have to stop movement to remove stun, even if it has a free action. This would then push stuff from under it and then prevent all further bantha movement.

Has anyone seen any rulings on this?

Large figure exits all spaces it occupied and enters all new spaces it occupies for each moved space. (It's probably in the FAQ.) No ending of movement is required. So yes, Parting Blow can be used if the figures were adjacent when(before) the Bantha moves a space.

Q: When a large figure moves, does it exit all spaces it
occupied and then enter all of its new spaces, even if some of
those spaces overlap?
A: Yes.

If the Bantha is stunned by the attack from Parting Blow, it does not lose movement points, but cannot spend any more movement points and thus needs to end movement. If it has an action to remove the stunned condition, it can continue spending the remaining movement points, unless it needed to end movement on top of other figures.

You kind of only partially addressed question 2 in your answer.

Can the nexu do parting blow while the bantha is moving over top of it? And does this end the bantha's movement?

I sort of tried to fully imply the answer. The moving figure (Bantha) is not ending movement just because the attack from Parting Blow or any other interrupt is performed. (Only if the figure becomes stunned from the attack, it cannot no longer spend movement points, causing end of movement - edit: due to either end of activation or needing to perform an action next .)

Parting Blow must also be resolved before the moving figure can choose to end movement. (Parting Blow happens after the figure has chosen to spend mp, but before the figure moves.)

Basically, if a movement triggers something else that interrupts that movement, that -does not- count as ending that movement.

Even the Stun, by itself, does not technically end the movement. But being stunned, the bantha can no longer voluntarily exit its space. Which forces it to end it's movement. And if it ends on top of another figure, that triggers the usual cannot-move-further rules.

Now, let's have a hypothetical scenario: a Command card exists that says 'Play when you receive a condition: discard that condition without suffering it's effects.' You play that card when the bantha is stunned. Then the bantha's movement -still- has not actually ended for game purposes, and it can continue moving normally.

Correct. You need to end movement to perform an action, but if an ability isn't an action, you can perform it without ending movement, and you don't need to end movement until you're out of movement points.

I think the trigger of the hypothetical command card could also be "during your activation". I don't think stunned in itself would end movement, so it it didn't take an action you could play the command card to remove stunned and continue spending movement points.