What does this information mean? To enter, you need to have finished The Search for Bloodskull Valley access quest OR currently be working on The Return of the Light heritage quest. Note: Speak to Amulius Ramio just outside to get flag for entrance. If you evac, you will be zoned out and locked for 11+ hours.
There are 5 waves of orcs (heroic ^ up to ^^^) that are activated when you first attack any orc in the courtyard outside the "battered wall." The second wave may take some time to begin, but they speed up after that. General Drull (quest mob for Return of the Light) is in the 5th wave. There is another named mob during the fight so make sure your quest updates before you leave.
It seems to have endless waves of orcs, but that's not true. There is one spotter (epic x2) in each tower, as long as they are up, two reinforcements (one for each tower) run from the narrow path in the East of the zone, to the center of the zone. When they get there (if they get there), epic bouncers and adds spawn for each reinforcement that reaches the center of the zone. This mob will seek you out and attack. Killing the spotters stops this process although one more bouncer mob usually spawns after each spotter is dead.
Once all the spawning mobs are down, and the mobs everywhere except the Arena are down, head to the Arena for a ring event that begins the next stage.
Now groups spawn at the two buildings (avoid the central tent at first), when they are down, the first named mob spawns with adds at the tent area to the West of the map (tent on the shore of lake). After each names pop, there are new spawns at the buildings. Overseer Maulic is the last named to spawn (3 nameds).
NOTE: As of Early 2015, this doesn't seem to have a lockout timer anymore, but it might be a bug that is scheduled to be fixed, so I'm leaving the timer as it is.