Stark listened to William's request and started preparing such special forces for him. William told him to send them at the gate where he was near it. There they'd meet up with other masters coming from his guild. And they'd listen to the orders of his vices.
Stark asked William about the weird behemoth that was fighting the monsters, and William simply said it was his without delving into any details.
As things were going as he planned, William returned to focus on the leopards around. He kept killing and collecting their cores and materials, didn't even hold back his hands and collected materials from monsters killed by city masters.
This wasn't the time for anyone to spare an eye over materials, but William was different. He wouldn't let a single item be lost when he got the choice to seize it.