Kalluto Zoldyck
Kalluto is Killua's youngest sibling and first shows up when Gon goes to retrieve Killua from the family estate—he's there with their mother. He's best known for his work with the Phantom Troupe, which he joined after they lost Hisoka. His stated reason for joining was to track down Killua, who'd gone missing.
Before that, Kalluto was seen helping his brother Illumi take out the ten mafia bosses who'd put bounties on the Troupe's heads. Once the Phantom Troupe moved into Greed Island, he officially became part of the crew and filled the spot Hisoka left behind. During the group's raid on Zayan's compound in Meteor City, Kalluto finally revealed he'd been using his position with the Spiders to search for Killua all along.
Content compiled by AnimeList.moe from publicly available sources.
