Upgrade Core (Low)

Introduction
A comprehensive list of cores can be found here. Upgrade cores are mainly used for upgrading items level(+1, +2, etc), more info can be fond here. Other types of force cores are as follows:
 * Upgrade Core (Low)
 * Upgrade Core (Medium)
 * Upgrade Core (High)
 * Upgrade Core (Highest)

Obtained
Craft: Basic Craft level 6 Field: Bloody Ice, Desert Scream, Green Despair Dungeons: Weakened Lake in Dusk, Weakened Ruina Station, Chaos Arena Lv1