Kadoc Zemlupus: A magus and the protagonist's senior. Leonardo da Vinci: A Rider-class Servant connected to the vehicle known as the Shadow Border. Sion: A magus who manages the Shadow Border and provides support to the protagonist. Master of Nemo. Nemo: A Rider-class Servant who pilots the Shadow Border alongside the Marines. Sion's Servant. Marines: Numerous small entities that are split-off versions of Nemo. Director Goredolf Musik: A magus who issues commands as the director. Meuniere: Provides support while piloting the Shadow Border. Others: The Chaldea staff members who have traveled together throughout the journey.

Class: Shielder. A Demi-Servant (Human + Servant). The protagonist's Servant and junior (kouhai). After losing her abilities as a Demi-Servant (Galahad's protection) at the end of Part 1, she dons the "Spiritron Exoskeleton (Ortenaus)" to stand against the bleaching of the world alongside her Master. Initially, she relies on fixed output from equipment that maintains a "Spiritron Awakening Rate of 60%," which puts a heavy strain on her body every time she fights. Consequently, consecutive deployments are difficult.

• True Name: ORT Xibalba • Class: Foreigner (Treated as Grand Foreigner / Grand Class) • Biological Classification: One Radiance Thing • Traits: Star Attribute, Threat to Humanity, Servant (During combat) An extraterrestrial invasive lifeform (the "Star-Eater" ORT) that slept beneath the South American Lostbelt. By utilizing a summary of human history and Lostbelt history through mirror-image duplication, it virtually constructed and summoned itself as a Heroic Spirit (Servant). A Servant that "should not have existed": A singular existence where ORT, an invader from outside Earth, is somehow recognized and occupies the "Grand" class—the highest peak of Heroic Spirits meant to protect Human Order. There are theories that it preyed upon (or defeated) the original Ultimate One of Mercury to take its throne, or that it is an invasive species/Ultimate One from a comet or the Oort Cloud. Details remain unknown. The metallic tentacles ORT releases when its outer shell is exposed (Skill Name: Ernst Union) instantly absorb, assimilate, and decompose anything they touch. If defeated in battle or if a certain number of turns pass, the deployed Servants are preyed upon and absorbed by ORT, entering a "DATA LOST" state. UFO Form: The true main body of ORT, a flying saucer-shaped form. It disguises its main body by placing tentacles and a giant creature-like mass resembling a spider beneath the UFO. Incidentally, this mass is waste material excreted from the main body—hardened skin keratin. This is the First Form. In the Second Form, it begins to walk truly like a spider. Third Form: Humanoid. Bipedal. Gigantic. It has a halo-like circle behind it. It registers itself in the Throne of Heroes, so even if it dies, it summons itself again. In the original encounter, the Lostbelt-side Foreigner Servant Kukulkan (the Lostbelt counterpart to Quetzalcoatl) turned herself into a sun and collided with it to prevent its re-summoning.