Sorry, Little Buddy
A few students with the Space Element tried to follow William's tracks, but escaping was a piece of cake. He simply passed through a portal to the tenth floor, waited for their presence to near, then created two portals leading to different locations.
With the Illusion Element concealing his aura to a considerable degree, the students had to split up to figure out which path was the correct one. He repeated this several times, marking each one with his Hunter Talent, then found a quiet place to relax on the thirteenth floor.
Leading them to the fourteenth floor in the beginning was of no risk to him, since the blocked-off area had been opened up after he defeated the Sun Stone Golem. William remained hidden until his marked targets returned to the tenth floor, then opened up his Status Panel.