You can find this enemy on Gaferis Ruins B3. You need to have Earth ability (destroy rock) to reach it.
Recommended Level: 30-35
Recommended time frame: After obtain Earth ability to destroy giant rock
Property: Undead and Crustacean
Weakness: Earth, non elemental
Initiate the battle with an earth ability (it will make him to have a bad status). Run around and wait until he attack and then counter. If you see him chanting the spell, then cancel it immediately (you need to use martial arte to cancel seraphic arte), also order others to “spread out”. Never stand in front of his face, his spell (aqua spell and and strength regression) can kill your character in one hit.
Sorey’s attack order: True fang (non-elemental) =>Shatterfang (crustaceans) => Phantasm flash (undead) =>Sword rain (crustaceans)