As Gon and Killua approach the registration desk, they are halted by an invisible, overwhelming force. Hisoka appears, warning them that they are not yet ready to set foot on this floor.
Containing the aura within the body to create a shroud. Zetsu (Null): Suppressing the aura flow entirely. Ren (Enhance): Producing a large amount of aura at once. Hatsu (Release): The personal expression of one's aura. Hunter x Hunter 2011 (Dub) Episode 28
They realize the massive gap in power between themselves and top-tier fighters like Hisoka. Their natural talent is highlighted by how quickly they master Ten (within hours, whereas most take years). As Gon and Killua approach the registration desk,