Thief Knowledge
シーフの心得 [thief no kokoroe] or 'knowledge of a thief' in Japanese.
Pictlogica

Obtain: Memoria Temple (Thief)
Use: required for EX Fusion of Thieves
Type: Grade Up Material, Rarity: ★★
Description: Material for EX Fusion and EX Alchemy synthesization
Other: an obsolete item. Was replaced by Soul of a Brave Man in early 2014
Category: Item