Interesting. I had interpreted the villains' multi-if statements literally
[...]
I wonder how this is actually SUPPOSED to be run?
The reason I think the way I do is that (again, AFAIK!

), they work just like regular monsters in terms of how they activate.
From the rulebook example, the skeleton has:
- If the Skeleton is adjacent to a Hero, it attacks that hero with a scimitar.
- If the Skeleton us within 1 tile of a Hero, it moves adjacent to the closest Hero and attacks that Hero with a charging slice.
- Otherwise, the Skeleton moves 1 tile toward the closest Hero.
The monster instructions say:
- Once a Monster has selected and followed one set of tactics, the Monster's turn ends. Do not continue to check its remaining tactics that turn.
So, the monsters' tactics have an implicit "... Else" as part of them: "If X, Then Y, Else If Z, Then AA, Else AB," and only one gets executed.
I don't see anything that says Villains are treated any differently - but, stressing this, my experience with the game is really limited*, so I could have missed it.
* As in, I've taken the pieces apart, looked at them, read the rulebooks, played a round or two to see how it works, and am awaiting the next non-D&D-playing get-together weekend to really play in a group.
