Ernst Frederick Egin

Ernst is authoritarian, obsessive and consumed by hatred of demons. He regards coexistence between Assiah and Gehenna as impossible and believes extreme actions are justified if they advance humanity's victory.

His worldview also shapes his treatment of his family. Rather than judging Rin independently, Ernst sees Satan's blood as contamination and considers Rin dangerous because of what he is.

He is capable of presenting his plans as rational necessities while concealing their full implications from the people whose cooperation he needs. His confidence in his own judgment becomes increasingly destructive as the anime-original conflict progresses.

Ernst's greatest power is institutional rather than physical. He possesses sufficient influence within the True Cross Order to command personnel, access advanced anti-demon technology and redirect major operations.

He supports large-scale weapons and research intended to destroy demons and ultimately eliminate Gehenna itself. His plans exploit Rin's unusual blood and demonic heritage as resources rather than treating Rin as a person.

Ernst is not established as a frontline fighter comparable to Arthur or Shura. His danger comes from authority, planning and access to the Order's military infrastructure.

Ernst appears during the anime-original storyline following the events adapted from the early manga. He approaches Yukio at a time when the younger Okumura is increasingly troubled by his own position and the Order's handling of Rin.

He presents an ambitious plan to eliminate the demonic threat and offers Yukio an important role within it. Ernst is revealed to have been responsible for condemning Yuri after discovering that she carried Satan's children, placing his ideology above his relationship with his daughter.

His supposed plan to destroy Gehenna ultimately involves using Rin's blood to open the Gehenna Gate. The experiment instead gives Satan an opportunity to intervene directly, and Ernst's attempt to control forces far beyond him collapses.

Ernst is exclusive to the 2011 anime's divergent continuity and does not occupy this role in the manga.

Yuri Egin is Ernst's daughter. Ernst rejects her relationship with Satan and condemns her after learning that she is carrying Satan's children.

Rin Okumura is Ernst's grandson, but Ernst primarily regards him as Satan's offspring and a potential tool or threat.

Yukio Okumura is Ernst's other grandson. Ernst attempts to recruit Yukio by appealing to his anxieties and presenting him with a path toward destroying Gehenna.

Satan is the being Ernst hates above all others and the father of his grandsons.

Mephisto Pheles represents an obstacle to Ernst's plans because of his authority within the Order and his protection of Rin.