[HE'S GONE MAD.]
That was Dahlia's first thought after hearing Prince Nero ask all the Soul Beasts there to be his new Soul Beasts.
The only person in history to gain more than two Soul Beasts was His Imperial Majesty Emperor Nikolai. It was the very reason the current emperor was hailed as the strongest man in the empire.
[Is Prince Nero trying to surpass his Imperial Father…?]
"Do you know how many Soul Beasts are here, you arrogant Crown Prince?" the supposedly fake Nero Roseheart asked. "Are you saying that you can free us by making us your Soul Beasts– all at once? Is your soul as huge as your ego?"
The fake Nero Roseheart made a valid point.
As far as Dahlia knew, the Soul Beasts were called that way because they lived in the soul of the de Moonasterio they served.
The emperor had the highest recorded number of Soul Beasts born within a single person.