Its essence is close to the soul, but at the same time, it is not entirely a soul. It is a processed remnant soul, possessing some soul characteristics, while also not being strongly restrained by sunlight, lightning, and such, unlike a remnant soul ghost, making it an optimized version of the soul entity.
The attack of the 'Spirit' can directly hit the soul and also cause a small amount of physical damage. Their attacks are hard to defend against and quite troublesome to deal with.
The intensity can be said to be exceedingly sinister!
But the price of being strong is the need for a long preparation time; it cannot be instantly unleashed and can only summon the 'Spirit' that has been prepared and successfully transformed.
In the blink of an eye, countless azure 'Spirits' filled the town, making the human world seem like a purgatory.
