Spellbook needed to learn 'Final Secret'.

Required:
Warlord - Lv. 75
Gladiator - Lv. 75
Destroyer - Lv. 75
Tyrant - Lv. 75
Bounty Hunter - Lv. 75
Warsmith - Lv. 75

To obtain this item, hunt the Hames Orc Overlord found in Blazing Swamp.