Helldiver Castrum Lacus Litore Guide in FFXIV

The first encounter of CLL is split into two bosses: Brionac, and the Helldiver. This guide will go over the latter of these two encounters.

Helldiver is a boss that is weak to magic, similar to other magitek in the Bozjan Southern Front. Healers and Casters will innately deal more damage, while phsyical jobs will benefit from having Lost Spellforge cast on them for the fight.

This boss must be killed within a few minutes of the other, otherwise it will enrage and wipe the raid. In order to avoid this, both teams shouild communicate the HP% of their bosses in Yell chat, and if one group is dealing significantly more damage than the other, they should slow down or stop their damage entirely in order to avoid a potential enrage and wipe situation.

• Chain Cannon: Telegraphed persistent line AoE.
• MRV Missile: Raidwide.
• Command: Lateral Dive: Spawns untargetable adds that do six line-Stack AoEs.
• Command: Suppressive Formation: Spawns unatargetable adds that do line AoEs across the arena.
• Magitek Missiles: Cleaving tankbuster on highest enmity target.
• Command: Infrared Blast: Spawns untargetable adds, players must take eight tethers.
• Command: Chain Cannon: Spawns untargetable adds that each cast Chain Cannon.
• Command: Dive Formation: Spawns three groups of untargetable adds that do three line-Stack AoEs.
• Command: Joint Attack: Spawns six adds that must be killed.
• Surface Missile: Spawns targeted circle AoEs under some players.

1. Chain Cannon
2. MRV Missile
3. Command: Lateral Dive
4. Command: Suppressive Formation
5. Magitek Missiles
6. Command: Infrared Blast
7. Command: Chain Cannon
8. Magitek Missiles
9. Command: Dive Formation
10. Command: Lateral Dive
11. Command: Suppressive Formation
12. Chain Cannon
13. Magitek Missiles
14. Command: Joint Attack
15. Command: Infrared Blast
16. Surface Missile
17. No new mechanics from here onwards

• If the Tunnel Armor dies, both bosses will immediately enrage and wipe the group. Prevent it from taking damage at all costs.
• Chain Cannon will damage the Tunnel Armor if aimed at it, so ensure it is aimed away when possible.
• Lateral Dive, Infrared Blast, Dive Formation and Joint Attack all damage the Tunnel Armor.As such, players should focus on being in the stacks for Lateral Dive and Dive Formation, ensuring that all tethers are taken on Infrared Blast, and killing the adds as quickly as possible during Joint Attack.
• The tethers from Infrared Blast will inflict a Fire Resistance Down debuff on players that take them. As such, players can only take one tether each during the mechanic.
• Upon killing Helldiver, adds will begin to infinitely spawn, and continue to do so until Brionac is killed, at which point you will be able to continue further into the duty. If Brionac does not die quickly enough after Helldiver, both will enrage and kill all players, forcing a wipe.

Clearing the first bosses of CLL will reward players with a personal treasure coffer that only they can see, which can be found in the entrance corridor to the next section. Some players may choose to mark this as it can be easy for newcomers to miss it inside the crowd of other players.

The next section is Bladesmeet - Albeleo and Prison Rescue. If you wish to view the alternate guide for the first bosses, please see The Grand Gates - Brionac.