Unbeknownst to all but Baddan and Replicus, the Incarnation of the Six Wild Exigencies, was a technique Replicus forged, first and foremost, by using [Unbound] on the unhatched eggs of Cluster beasts.
The Special Bonus Random Upgrade worked wonders with procuring rare creatures within the Null Verse, though admittedly, most of them tended to be akin to the Chubby Remnant Child of Polarity – 'living' creatures that weren't exactly living creatures. Some turned out to be consumables, others turned out to be accessories and some... were more like plants.
Some seemed to have souls, and others didn't.
It was only after many trials that Replicus managed to get genuine beasts which he then used [Wealth of Spoils] on to grant abilities in their infancy before grooming them. For some, he merely enhanced those they already had.
These same beasts were what made up Baddan's technique.
