Tower of Courage
The Tower of Courage, abbreviated as ToC, is the name of an area in FoW, and the main quest in that area. The team spawns near ToC when entering FoW.
The quest, given by Rastigan the Eternal, requires you to kill the 5 groups around the Tower itself, each consisting of 2 Shadow Rangers and 1 Abyssal. Once the group nearest to Rastigan is dead, he'll start running towards the Tower, and when the rest are dead, he'll run all the way to the gate. If nobody is in compass range of him, he will not start running. Rastigan is hostile to all enemies, but he will not attack them, so if any are left in his path and he doesn't break aggro, they will kill him, causing the party to fail.
Upon arriving at the gate, Rastigan will begin a ritual to open the Tower, and when the gate opens, 2 Abyssals and Shadow Lord Vogris will spawn inside. Killing Vogris completes the quest, but Rastigan remains vulnerable until he loses aggro, so the Abyssals need to be killed too.
Curiously, taking the quest from Rastigan does absolutely nothing: all relevant mobs are spawned when entering FoW, and the quest can actually be completed without anyone accepting it. However, you need to take the reward in order to accept the following quest, Lightning Forest.
There is a narrow pass in the south that leads to Beach, and a road leading north to Battlefield. Everything in between is considered the ToC area. All the enemies here are Shadows, and they are hostile to the neighbouring Skeletals on Battlefield, the Dryders, Driftwoods, and Skales on Beach, and the Shadow groups that spawn when the quest Lightning Forest is taken.