"Monstrous Priest (1)" is episode 167 of the Berserk manga.
The impact of ramming Mozgus sends both him and Guts flying into the outer wall of Albion, destroying a large chunk of it, frightening the refugees who stand in its shadow. Guts stands up from the wreckage, still atop the wall, but the refugees mistake him for a black demon and fear that Mozgus has been killed.
Guts' mind is elsewhere. While running down the Tower of Conviction, he caught sight of a small creature that was moving in the opposite direction. He looks up at the Tower, expecting to see the Demon Child. Instead, looking up has allowed him to see one of the twin disciples fly directly toward Casca. Though Guts is too far away to help her, Isidro has also noticed the disciple, and grabs Casca's arm and pulls her to the ground, narrowly avoiding the pseudo-Apostle. The other twin follows soon after, and is seen by both Guts and Isidro. To make matters worse, Mozgus awakens and forces himself to a standing position directly behind Guts then attacks, with Guts blocking the attack just in time.
The second twin disciple swoops down to grab Casca, but Jerome is ready. With one swift move of his sword, he grazes the disciple and forces it to veer off-course, joining its brother in the air.
Mozgus has stood up, though being quite tall as a human, his new form is even taller. He has completely transformed, now having more of a reptilian appearance than one of a bird; his skin is covered in scales, his muscles swell and his wings have curled up to form enormous clubs. His clothes no longer fit, and he tears them as he moves.
However he has retained his sanity. He announces that he will punish Guts for his insolence, and extracts his book of scripture, which has nearly been cut in half. It has taken the most of Guts' prior attack, allowing Mozgus to live. He orders the twin disciples to focus their efforts on capturing Casca and killing Jerome, Nina and Isidro while he deals with Guts, partly out of devotion to his faith and partly out of revenge for Guts having killed his other disciples.
Guts and Mozgus attack at the same time, with Mozgus' wing attack missing Guts entirely, but the Black Swordsman's strike hits its mark. His sword connects with Mozgus' head, but deals no damage: Mozgus' scales and new strength make him nearly impervious to damage.
The twin disciples wield their signature saws and fly toward Casca, Isidro, Jerome and Nina, distracting Guts. With the Black Swordsman's back turned, Mozgus decides the time is right to reveal a hidden weapon. He unfurls his wings, each feather of which is curled into a fist-like shape, and thrusts them at Guts all at once.
Characters in Order of Appearance