Post: #3

You seem to have got the idea of @EnvironChange, so I'm not explaining it.

Few tips though: First, you don't need to keep a tag for the players in the area, <region.clients> will give you that. Second, your server can handle a simple looping function just fine so @EnvironChange is not a bad choice in this case but keep in mind it will trigger simultaneously on multiple mobs which is a little redundant. Because you want to modify their stats, which is a combat related thing. So if I were you, I would let the mobs out of combat just go around their business and select a trigger that only affects mobs that are fighting (say @GetHit, or something similar). A simple example: