Berserker's True Name is Megalos (メガロス, Megarosu?), the alias given to a Berserker Heracles whose Saint Graph is highly modified by Scheherazade using her Noble Phantasm in conjunction with the power of Phenex. Deciding that names like Gigas or Gigant would likely offend the hero due to being enemies of the Olympian Gods, Da Vinci and Mash name him Heracles Megalos (巨英雄ヘラクレス, Giant Hero Heracles?), and then further dissociate him from the regular Heracles by deciding to just call him Megalos.
Agartha: The Mythical Subterranean Society
Berserker's Saint Graph is highly modified, towering over his already massive 253cm self. His output, endurance, and Divinity have greatly risen. He possesses the Skill Enormous Twelve Labors.