The final boss of Part 1 of Honkai Impact 3rd, a MANTIS of the Previous Era, and the strongest warrior of humanity. As the Sovereign of World Serpent, he refers to Kiana, Mei, and Bronya as "descendants." He wields the Kaslana family's signature weapon, Judgment of Shamash. Shamash is a Divine Key created from the core of the 7th Herrscher, the Herrscher of Fire. Its forms include the dual pistols [Judgment], the [Greatsword] form activated by the command "Cleave, Shamash!", the [Might of An-Utu] which manifests when infused with Honkai energy, and the [Transcendent] form of Shamash's Judgment [Parvati] which changes shape when infused with the Authority of Finality. Using the Parvati Honkai Beast genes, he can freeze even the flames of An-Utu. Through [Project Chimera], he possesses numerous Honkai Beast genes in his body, allowing him to use Active Honkai Reaction. His forms include Normal, Deliverance, and Savior. He stands against Kiana, Mei, and Bronya on the moon, stating that if they cannot surpass him, [Project Stigma] will proceed as planned. He awakens as the final boss [Deliverance] Kevin. Though he fought Kiana and her group with all his might in his Savior form, he was ultimately defeated and perished after a final duel with Kiana as a "human."

The protagonist of Part 1 of Honkai Impact 3rd. Currently, she is a girl dreaming of becoming the "strongest Valkyrie." She shares a special bond with Raiden Mei; when Mei tried to jump off a roof at Chiba Academy because she was suffering as the Herrscher of Thunder, Kiana caught her hand and saved her. She also gets along well with Bronya, Himeko, Fu Hua, and Theresa. She is destined to awaken as the true Herrscher of the Void and later become the Herrscher of Flamescion and the Herrscher of Finality. Herrscher of Flamescion: She wields Himeko's memento, recreated as the "Flamescion Greatsword." She is incredibly powerful, possessing the power of four Herrscher cores. She awakened after hearing Himeko's voice in the Theater of Domination. Herrscher of Finality: To stop Kevin, she seized the Authority of Finality and eventually accepted the Cocoon to become the true God of Earth.

The daughter of the CEO of ME Corp and Kiana's lover. She was the central figure of the 3rd Honkai Eruption at Chiba Academy. She is the Herrscher of Thunder, the Herrscher of Origin, and a visitor to the Elysian Realm. When the world suffered due to her awakened Herrscher personality at Chiba Academy, she tried to sacrifice herself by jumping off the roof but was saved by Kiana. She is a skilled cook. Weapon: Katana.

A gaming enthusiast and comrade to Kiana and Mei. She is the Herrscher of Reason and the Herrscher of Truth.

A Major at St. Freya Academy and the teacher of Kiana and the other students. She passed away after giving Kiana, who had become a Herrscher, her [Final Lesson].