Omega

''This page is about Omega–Ryuzu Shima's body which is currently being used by Echidna. For other copies from Arc 4, see Ryuzu Meyer (copy) and for the original Ryuzu, see Ryuzu Meyer (original)''

Omega (オメガ) is a clone of Ryuzu who contains the soul of the Witch of Greed. Before the fall of the Sanctuary, the clone was known under the name of Shima–one of the original four clones who were tasked with overseeing the Sanctuary itself.

Accompanied by Colette, Palmyra, and later Lysa, Omega was last known to be in the Holy Kingdom of Gusteko.

Appearance
After possessing the body of Ryuzu Shima, Echidna naturally took on the physical form of her host and named herself Omega. In terms of her appearance, Omega is a petite young girl around ten to twelve years of age, though in reality, she's well over four centuries old, predating even the Great Calamity. Her beautiful yet pale face is adorned with a long refined nose and almond-shaped cyan eyes, and her body is clad in a large white robe that drags along the ground with the sleeves being longer than her arms-she looks exactly like the Ryuzu Meyer copies from the Sanctuary, but with a white-coloured robe instead of a dark one. As Ryuzu Meyer was a half-elf, Omega's ears are inhumanly pointy. Her long fluffy peach-pink hair flows down her back and is slightly curved outwards. Befitting a girl of her physical age, Omega is rather short, failing to reach even halfway up Subaru's chest.

Personality
Ryuzu Shima was against freeing the Sanctuary due to seeing the original Ryuzu's memories 10 years in the trial and had partly been manipulating Garfiel behind the scenes to make sure it didn't happen. She entered the grave in an attempt to rescue Garfiel but was forced to take the trial. In the end this meant she broke her contract with Echidna. As punishment Shima was duly stripped of her position as an overseer and was made to live with other mindless clones in the forest, donning the white robe as a result.

After being possessed by Echidna's soul, Omega is essentially Echidna from the Castle of Dreams, but in a different body. She retained all of her memories and thoughts, but was forced to forsake most of her magical power in order to retain her full self. Having been born anew, Omega mostly spends her time observing and adventuring, trying to learn as much as possible about the world she is so unfamiliar with. It should be kept in mind, however, that Omega is in fact the Witch of Greed from the Castle of Dreams, rather than the Witch of Greed who roamed the world before the fall of the Witches.

History
Roughly 10 years before the events of Arc 4, Garfiel ran into the Tomb and challenged the Trials. Out of concern for him, one of the Ryuzu copies–Shima–followed suit and accidentally underwent the first Trial. Seeing this as a good opportunity to yet again kick off her experiments with Soul Transference, Echidna used that occasion to latch a tiny bit of her soul onto her. For the following ten years, she slowly filled the host with her soul, bit by bit. A decade after kickstarting her new plan, Echidna was finally given an opportunity to escape–and so she did. On the day when the snow fell in the Sanctuary, Echidna somehow managed to pour in the last bits of her soul, and escape the Sanctuary after four long centuries.

After the fall of the Sanctuary, Echidna managed to completely transfer her soul into Shima and renamed herself Omega which means "the end", based on Subaru's memories of his original world. She then decided to take it slow and first get accustomed to the new body.

She decided to go to Kararagi, her goal remaining unknown. While on her journey, Omega met Colette–who had been shunned from her village for being a "witch"-and her friend Palmyra. In actuality, it turned out that she was unconsciously behind the killings as she'd come under the possession of a Meteor that transformed her into a beast. The two girls decided to travel with Omega after the latter failed to straighten things up with the villagers.

Abilities
Magic (魔法 Mahō): Since Shima's body was not the most suitable host for Echidna to possess, she was forced to leave out her experience with magic. She is still familiar with the usage of magic but is unable to properly cast more advanced spells. According to her estimates, it will take her roughly two years to regain all her skills and powers.
 * Goa (ゴーア): Omega is able to manifest a blaze of fire to incinerate her foes.

Miasma: Omega can project the soul of the Witch of Greed, making it appear as if she was physically standing by Omega's side. By doing so, Echidna starts emitting an intense aura of wickedness and madness which is enough to drive people mad and kill them in thirty seconds. It's mentioned by Echidna that a Sage could endure her aura.

Unknown Ability: Shima can smell the Witch's miasma, something that only a few individuals in the series so far are capable of doing. This is likely due to her connection with Echidna before she completely took over Shima's body.

Equipment
 * Pyroxene Crystal (輝石 Kiseki): Omega carries a necklace with her, that contains the five souls of the other witches, Minerva, Carmilla, Typhon, Sekhmet and Daphne in it. She can freely converse with them, but she is unable to bring them out of the crystal and have them materialised in the world.

Trivia

 * Contrary to popular belief, Omega cannot use the other Witches' Authorities.
 * Along with Rem and Reize, Ryuzu Shima is one of the few characters capable of smelling the Witch's miasma.
 * While Garfiel claimed that he could smell the Witch's miasma, it was actually Shima who could smell the miasma off Subaru.
 * Despite her scene from the end of Volume 15 being omitted in Episode 50, Omega made her debut in Episode 49.
 * As Emilia entered Echidna's laboratory and started enquiring about the circumstances and speculating about the identity of Ryuzu encased in the massive pyroxene crystal in the middle of the room, the attention is briefly given to Ryuzu Shima, who–with Echidna's distinct voice–states the following–"Unbelievable. To see this, and that's the first thing you can think of?". It's presumed this scene serves as a substitution of the final Volume 15 chapter titled Extra: ...The Second Coming which was, as mentioned before, omitted from the final episode.
 * In the Web Novel, Echidna named herself Omega because Subaru named her that, implying that Echidna's new vessel is the original Omega copy may have merged with the original Ryuzu sealed within the pyroxene crystal, similar to how Shima sacrificed herself by vanishing with the crystal and ended up becoming her new vessel in Volume 15.
 * Since the Omega copy was removed in the Light Novel, Echidna chose the name Omega on her own at the end of Volume 15.