Everyone knows how Gondor has it's famous Signal Beacons , and how they can be useful for warning others (or even just a non flamable light source), especially on servers. But not just Gondorians use these beacons, that's for sure.
My idea is that Evil gets some sort of signal beacon/signal fire (since only Gondorian players can make them), most likely Mordor. Since Mordor is such a large place, even one swarming with Orc guards, it needs some way to communicate if a region is in danger.
Mordor Beacons would work exactly like a Beacon of Gondor, except they only light Mordor Beacons (It wouldn't make sense for a Gondorian to light a Beacon of Gondor to signal a Mordor Orc). These would look more like braziers than bonfires, and crafted out of Mordor brick instead of cobblestone, but still made out of logs.
(Note this is most likely laggy due to beacon streams)
Morgul Beacons would act similar to the Vanilla beacon, where they shoot up a beam of light, but are fueled by Gulduril, and are doused by covering them. They would offer no potion effects to players unlike the Vanilla beacon, but just give the light into the sky (Note, this last only lasts for a short period of time to compensate, up for debate). They are crafted with Gulduril crystals instead of Logs, and then built by placing Gulduril Blocks in a 3x3 space, then placing the beacon on the top middle. These activate other Morgul Beacons.