Refined Soul

Refined Soul or simply a more complete Soul Core are remnant of the Soul of a deceased monster. These are extremely rare.
There are different quality based on Monster grades.
Soul cores dropped from a dead Minion Level monster is called Minion grade Soul Cores
Soul cores dropped from a dead Warrior Level Monster is call Warrior grade Soul Cores
Soul cores dropped from a dead Command level monster is call Command grade Soul Cores
Soul cores dropped from a dead Monarch level monster will be Monarch grade Soul Cores