Server ran player accounts, mercenaries, "friendly" mobs or NPC's that attack -- is it possible?

[GrimmestDays]

Hello.

On the server that I am working on I am wanting to build a more realistic atmosphere for RO. One of the things I have done is enable mobs to use warps so they can chase players in to towns (more realistic IMO than them simply stopping)..

I want to take that a little further though and have guards stationed at town entrance/exit points so they can fight any mobs that enter the town map.

I've read around and the best I could find that would fit the bill was using the monster script command for summoning a human mob that would serve as a guard with AI type 8 set. This works decently but there's a problem; players can still attack those friendly mobs..

Is there any way for me to make a mob un-attackable? If not, is server ran player accounts, mercenaries or NPC's that can attack possible?

Note: I've considered using OpenKore already to handle the server ran player accounts but its memory use is a bit higher than I would like so please do not suggest it..

[Nameless2you]

One of the things I have done is enable mobs to use warps so they can chase players in to towns

Go read battle conf please.

I doubt anybody would suggest using openkore. For the unattackable mob I suppose there are a couple of people that could make an easy mod for that.

[GrimmestDays]

Eh? What exactly am I supposed to be seeing in battle.conf?