How to obtain this mission
After accepting this mission, go speak to Prince Trion. After a cutscene, go gather a full level 60+ party (there is no level cap for the BCNM fight). Mages will need several yagudo drinks; melees will need several hipotions and Icarus Wing. Level 60+ melees should sub Samurari if possible for a job ability that increases TP.
It is recommended that all party members be at least level 60 as you will not aggro the weak mobs. This is very important once you enter the Keep, as the teleport devices will cancel your Invisible effect.
The party should have at least 1 BLM, a tank that knows how to hold hate, couple support mages, and 2 melee damage dealers. Once the party is formed, Teleport-Vhazl into Xarbacard. From the telepoint, head due west and you will end up at Castle Zavhl Baileys.
Upon zoning, go straight until you encounter the first intersection. Make a left turn at this intersection. You will eventually find a small flight of stairs to go down. Once you go down the stairs, turn right and follow the left wall and you will enter the Orc section and map 2.
Go through the area to the west again. Eventually you will zone into Castle Zvahl Keep.
Once you enter the zone, you will have to open several gates, very often in front of mobs that detect on sight. If the entire party is level 60+, the mobs will not pose a threat. Work your way to the top of the map on Map 1. In Map 2 find the way to the west exit of the map.
Now you will encounter a series of teleport devices. These devices will cancel the Invisible effect after they are used. Once you use the last device, run to the west exit of the map where you will find a zoneline. Open the door and exit into the Throne Room.
Rest to the max. Once the party is ready, gather in front of the door. When you enter, a cutscene will happen and the fight begins. Cast the prefight buffs before getting closer.
The Shadow Lord has 2 forms. The first form is the most dangerous form. He will spam the Invincible move once he is at 50%. Invincible does not protect him from magic, thus this is why a BLM is needed. Melee should use their weaponskills whenever they can unless he is in this state. The mages need to move up the stairs and heal the tank. Once Shadow Lord starts spamming Invincible, the BLM need to nuke him like no tomorrow with level III and IV Magics. Once the melee starts dealing damage again, the BLM should be resting.
After the first form is defeated, a cutscene will appear. The second form will show up after the cutscene and he is not going to wait for you to rest. The melees should use their 2 hour abilities and Icarus Wing if possible to have TP for their best weaponskill, and spam their Hi-Potion macro. Shadow Lord will do nothing but a AOE attack. Mages should cast their Curaga spells. This form of Shadow Lord only has 4000 HP and should die quickly. After this form is defeated, another cutscene occurs. Once the cutscene ends, you will be transported back to the enterance of Castle Zavhl Baileys.
Now report back to Prince Trion for another cutscene.
Rank 6, 20000 gil