The Palaces and the Metaverse are the product of the cognition of individuals and society, with those reflecting how they perceive the world. Yaldabaoth controls society from the shadows using the masses' cognition in Mementos. Once he sets his plans in motion he merges Mementos with reality, using the cognition of the public to deny the existence of the Phantom Thieves of Hearts. The masses' cognition begins to erase them, plummeting the already low support rate of the Phantom Thieves in the Phantom Aficionado Website to exactly 0%. The protagonist finds himself in the Velvet Room where "Igor" tells Caroline and Justine to execute him, until they awaken as well and he fuses them into Lavenza, in which the two face Yaldabaoth. He offers the protagonist a chance to join him, and if he refuses, Yaldabaoth allows them to remain in existence for his own amusement and it is revealed that those who are banished by the masses' cognition are actually imprisoned in special cells inside the Velvet Room, which has been merged with Mementos after its infiltration and capture. The masses' cognition is later used against Yaldabaoth in the final battle, where their cheers heal and protect the Thieves from the Rays of Control and the reverse manipulation also awakens Arsène into Satanael, who kills him with a shell imbued with the combined might of the Seven Deadly Sins.