After exploring deep enough in the Deep Dungeon, located in the northeast corner of Elsendor, players will learn about Serpentarius, the thirteenth Zodiac demon, and unlock the ability to battle him. Defeating Serpentarius awards the player a Serpentarius Emblem, which is needed to purchase some extremely powerful items that are sold in the Deep Dungeon shop.

This is one of the most difficult bosses in the game. You can fight Serpentarius as a group, as long as everyone in the group has unlocked the ability to fight him by exploring the Deep Dungeon. Every member of the group will receive the reward. A party of level 125 or higher players is recommended.

If you have three or fewer players in your group, you can hire Byblos, the ancient guardian of the Deep Dungeon, to aid you in the battle.

You can only kill Serpentarius once per reboot.

To get to Serpentarius, go to Floor 0 in the deep dungeon elevator.


Locations Deep Dungeon

Scanner Data
Desc The thirteenth Zodiac Demon, Serpentarius, stands before you.
HP 1,300,000 MP ? XP 18,900,000 Level 250
C. Types Demon
Weak ?
Resist ?
Immune ?
Absorb ?

Items and Abilities
Drop Serpentarius Emblem Steal None Secret Hunt None
Lore None
Abilities Snake Carrier (Magic)
Poison Frog (Poison)
Resisted Gravija (Gravity)
Gravija (Gravity)
Midgar Swarm (Earth)
Banish Ray (9999 Dark Damage)
Firaja (Fire)
Blizzaja (Ice)
Thundaja (Lightning)
Comet (Magic)
Light Pillar (9999 Light Damage)
Necrotic Energy (Drains a random attribute for 7-8 rounds)
Nullify Healing (Blocks healing)
Zodiac (Magic)


If you want to solo this boss, you should hire Byblos for 1 million gold. Byblos is around as strong as a level 200 Human character and is extremely valuable for the fight. He does not get attacked by the boss; you will receive the full damage.

You must kill Serpentarius in 100 rounds, or else you will be killed. You cannot exit the boss fight once you have started it. The fight lasts longer than Auto-Life, so if you are in the middle of a fight and do not believe you can win, let it kill you so that you don't lose Auto-Life and take an XP-loss death.

Equip some kind of poision immunity (like Ivy Bracelet) to counter the Deadly Poison. Without it, you will take massive damage from the Deadly Poison.

Go into this fight with more HP than you think you need. The boss will very likely drain your vitality at some point in the fight. Elemental resistances are extremely valuable; try bringing a Venetian Shield or Zeidrich.