Tendrils of dark mana wrapped around the bodies of Grokus' slaves so quickly that they could not react before it wrapped them from head to toe, sealing them in confined cocoons that did not allow them to use their mana.
Grokus' eyes snapped wide open when this happened, as he did not expect Leon to have been able to do that. When his spell broke apart and Leon escaped earlier, he did not even entertain the thought of Leon having snatched his control of the mana. All he knew was that Leon somehow broke the spell apart by untangling the complex weaves of mana. He did not dare think that Leon had instead snatched control of his mana from him without him knowing.
The reason why he now knew was because the way that the mana cocoons were woven around his slaved was exactly how he weaved his spells with the help of his totems. Surprisingly, Leon had been able to do the same without using a totem, while he had used five!