Quest "Legion's Hunter" Victory states:

"If each hero is on the Exit:"

[...]

The Heroes win!

Setup:

Overlord has one monster on Exit tile.

Three heroes are on Exit tile. No free squares available on Exit. One hero outside Exit tile.

Question :

Can heroes win by stacking two heroes at the same square or do they need to kill monster first and move last hero into empty space?

I don't think so, but this is a really interesting question.

I would say you need to end your movement on the tile, but I can see a decent argument. (You're ON the exit it if you move through a space containing a hero...)

The heroes need to kill the monster or move it. Two figures cannot occupy the same space, so the heroes need to be all on separate spaces to be simultaneously occupying.

Thanks for the replies!

I assume same logic applies to other cases when game checks if hero is in specific space or not? Eg. moving off the map requires edge of exit tile to be empty from both heroes and monsters:

"To move off the map, the figure must move to one of the edge spaces (marked below in red) on the entrance or exit tile and then spend one movement point." (Rulebook, page 9)

I'd need to look around for the clarification of this, but:

Since the movement is continued, I think you could move through the edge space and off the map. That doesn't require occupying the space.