Ghostblade 4-Star Evolution Gem

The Gem with the purest power of the astral realm can enhance the star level of the star spirit "<Dark Night Ghost Blade> Rin."
It can be given to the astral spirit through the "Gift" button in the astral spirit interface, raising the star level up to 4 stars.
You must have a 1 star astral spirit before gifting, and it raises one star level at a time. After advancement, the original star energy will reset to zero.