In "The Binding of Isaac", what is the name of the final boss that you fight in The Void?

In The Binding of Isaac, the final boss that players fight in the Void is named Delirium. Delirium represents Isaac's deteriorating mental state and distorted perceptions, serving as a metaphor for the chaos and confusion he experiences in his journey. The fight against Delirium is challenging, as it constantly transforms into previous bosses from the game, requiring players to adapt and strategize on the fly. Defeating Delirium marks the culmination of Isaac's journey, as he confronts his own inner turmoil and finds closure.