Items required
Adamantine - 1
Star Fragment - 3
Curse Spike - 2
Cost
1000 Gil
Damage Increase
+25 to base Str value
Where to find the items
Adamantine
Easy to get:
1) Mug the boss at FH
2) Refine 10 from Minotaur's card using Quezacotl's Card Mod
3) On Long Horn Island, there are usually Adamantoise that drop Adamantines
Star Fragment
These are dropped by Tri-Faces and Iron Giants (high level). Both are found in the Deep Sea Deposit. Iron Giants are also found in Esthar and Ultimecia's Castle
Curse Spikes
Defeat Tri Faces in the Deep Sea Deposit
Good Luck!