Well, I don't want player-killing unless both players consent, and I also leave it to them how to handle it. I'm not running the game with a system in mind; most of my experience has been with logic-based turn combat, with observing peers judging. That way, it allows for fluidity and creativity, while still making sure that people don't just godmode their way out of the stratosphere.
To make things absolutely clear: This game is focused on what occurs INSIDE of the Keep. The demons are meant to be a nigh-insurmountable environmental circumstance to add pressure and cause. The real purpose of this game is 'Lock some Horde and Alliance characters in a box, and see what happens'. The demons are meant to be the box, that's all. Actually changing the situation is something I plan on controlling by managing them as NPCs. I'm acting as a DM with a character in-game. It's not good for a goal-oriented game, but this isn't about winning or losing.
Anyways, if I've brought people in under false pretenses, you have my apology. I'm always interested in the Warcraft universe, and I'm sure a less drama-oriented game could come up in the future. But furthering the plot of this game is about interacting with the other players, not fighting the demons. Try and treat it as such, please.