Hunter X Hunter 2011 Episode 5 -

In the manga, the does not actually swallow Gon and Killua.

A man appears claiming to be the real examiner, accusing Satotz of being a "Man-Faced Ape." Hisoka resolves the dispute by throwing cards at both; Satotz catches them, proving he is the real examiner, while the imposter is killed. Hunter X Hunter 2011 Episode 5

senses something is wrong and returns to help his friends, striking Hisoka with his fishing rod just as Hisoka is about to kill Leorio. In the manga, the does not actually swallow Gon and Killua

As the applicants exit the underground tunnel, they enter a foggy, swampy area filled with deceptive creatures. In the manga

Leorio and Kurapika witness Hisoka's violence. While they initially run, returns to fight, unable to ignore the cruelty.