You need to kill this boss (the moving one) four times.
Drop: Forshura's Arm
Quest "Revenge"
General Feng: Null
(401 512)
Water Melee
Level ? 4.000.000 HP
This boss has a physical aoe and an aoe debuff (reduce max HP)
Drop: Horn of Feng's horse
Quest "The Request"
Cosmoforce: Null
Lot Mode (413 525)
No elt Melee
Level ? 4.000.000 HP
He has four buff (increase his patk, matk, pdef and mdef)
Drop: Giant Ape's Tail
Soulripper: Null
Lot mode (380 509)
Metal Melee + Magic
Level ? 3.223.518 HP
Drop: Antenna of Consumer of Souls
Astralwalker: Null
Lot Mode (401 525)
No elt Melee + Ranged
Level ? 5.000.000 HP
When his life go under 75% (a minion appeared).
When his life go under 50% (two other minion appeared).
When his life go under 25% (three other minion appeared).
Drop:
• Wheel of the Seven Luminaries
• Astral Stone
• Power of the Seven Luminaries
Quest "Real Horror"
Ancient Evil: Lethal Vengeance
Lot Mode (401 530)
No elt Melee + Ranged
Level ? 4.200.000 HP
After a few hit three minion appeared (a ranged, a magical and a melee)
He has a random aggro (with a front physical aoe and an aoe debuff: increase casting time)
He has four buff (increase his patk, matk, pdef and mdef)
When he has less than 25% hp:
• he has a mana burn and debuff (decrease accuracy)
• he has more random aggro
Drop:
• Ancient Devil's Horn
• Dust of Devil
• Ancient Devil's Soul