Upgrade Core (Ultimate)

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 upgrade cores are as follows:
 * Upgrade Core (Low)
 * Upgrade Core (Medium)
 * Upgrade Core (High)
 * Upgrade Core (Highest)
 * Upgrade Core (Ultimate)