Vassago Casals (ヴァサゴ・カザルス, Vasago Kazarusu?), known as PoH (プー, Pū?) in Sword Art Online (SAO) and Project Alicization, is a reoccurring character in the Aincrad Arc and the secondary antagonist of the War of the Underworld sub-arc of the Alicization Arc. As a member of a Korean crime syndicate, Vassago was ordered to log into Sword Art Online after it had become a death game, in order to indirectly assassinate a person already trapped in the game. Harbouring resentment against East Asians due to his troubled past, Vassago as PoH decided to instigate other players to kill each other and eventually founded «Laughing Coffin», the most infamous player-killing guild in the game. Eventually, PoH betrayed his own guild by disclosing the location of its hideout to the Clearers to facilitate a massacre between the two groups, while he himself avoided the clash. Vassago was one of the players logged out from the game on November 7, 2024, after which he returned to America and found employment with a private military contractor.