Be very careful of the Dread snout group aggro on the few Maple Story Mesos
You'll need 3 boxes eventually, so pick the most Maple Story Mesos convenient ones. Be very careful of the Dread snout group aggro on the few pedestals in the area, clear these first. Rosch is on a raised area along the left wall after the turn that you can pull him down from without stacking boxes.
Fight him ONLY when you have a clear open area, mobs in his group tend to get stuck in the walls.
Killing him just might get you your TP shard. When you're ready to complete the quest, stair step three boxes up to the area you pulled Rosch from and click the Throne to zone out. Congrats! But unfortunately you don't get to keep the Harclave buff!
Also, get out your best encounter-damage and solo damage spells regardless of mana cost. Do your best to only take on one group at a time, and you should never need to run.
When you've taken care of the King and gotten the update, its time to go after Rosch Val Gornas in the depths of Harclave. Wind your way downward (remember, one group at a time!) until you get to a skeleton area. Undead gnolls are guarding boxes around the periphery.