Okay I was testing one map and there was one specific entity in multiplayer map. It didn't do a thing before I shot it after what I started to shoot at me.
Anyway I made short experiment by creating small level putting same entity, way point and goto player... for my wonder it started to move and even shot at me... however ... for some strange reason this entity did not have much ammo so he shot me only few times.
So thing I am now wondering for most is that can AI put somehow with few trick into maps ? I don't know But I am going to find out
Yeah server can see the entity and what it’s doing but any one can feel the entity attack and even be killed by it. The message for that is always died mysteriously or was killed mysteriously, Can’t remember the exact phrase. I've been trying to think of how to trigger some effects to draw other players in multi to the current attacking invisible entity but have not come up with any thing yet.