Kuzon knew he was making a few assumptions in his analysis.
In the first place, he hadn't confirmed that Legris needed to use his existing darkness to form the cocoon, or that Legris couldn't just make more.
To compensate for this, however, he had to come up with a plan with the possibility of that in mind—a plan that accounted for Legris' potential counterattack!
The first and most important part of it was his golden mannequin.
The mannequin served as a decoy to distract Legris and was eventually used to bind him. Of course, Legris was able to easily disarm the strings, but not before Kuzon put his plan into motion.
'[Marionette Butterfly].'
Unlike the regular Marionette Worms, this one blended in properly with its surroundings and host, making it indistinguishable from the air or one's skin.
Since it took on the properties of its host, Kuzon was able to make it indistinguishable from Legris' own self.
