The boss, Fallen Archbishop Andreus marks a major turning point in Lies of P where the player is no longer fighting robot Puppets, but malformed monsters ripped straight out of your worst nightmares. Andreus is one of the toughest bosses in the game, and we’re going to teach you how to destroy him.

source https://www.windowscentral.com/gaming/xbox/lies-of-p-boss-guide-how-to-defeat-fallen-archbishop-andreus