Every Chosen One has someone to balance them, like yin and yang. This person is called the Osirian. The Chosen One's Osirian is their complete opposite (personality, gender, etc.) and protector. Rufus Zeno was Sarah Frobisher-Smythe's Osirian. The identity of Nina Martin's Osirian is Eddie Miller (although Eddie no longer has his Osirian powers). Nina and Eddie may one day become more than friends or may become very close but still remain platonic. The Osirian has powers like the Chosen One, stated by Senkhara who said the Chosen One could be replaced, but those are still unknown.
The Osirian is based off the Egyptian god Osiris. It is not destined for the Osirian and The Chosen One to be romantically linked but it may happen due to the fact that the Osirian is very protective of the Chosen One. In the Season 2 finale, the Osirian (Eddie) destroys Senkhara (in Nina's body) with her owncrown.
Ironically, even though the Osirian longs to protect the chosen one, they can not be together. This is discovered in the Season 3 premiere, when Fabian thought Eddie was having a secret relationship with Nina but it is later found out that Nina was away because the Osirian (Eddie) and the Chosen One (Nina) can't be together. In the Touchstone of Ra, Eddie used his Osirian to break the Touchstone of Ra and destroy Sophia Danea. He saved the house from falling down. The Osirian is dead, but the boy lives and The Chosen One stays alive but with no Osirian. Before knowing who the Osirian was it also seemed possible for Jerome Clarke to be the Osirian since he was the Osirian in Das Haus Anubis and banished the spirit of Senkhara just like Eddie did.
When Eddie got to the library, the Frobisher gem was glowing in his hand. Nina walked towards him in awe and asked "You're the Osirian?" He nodded and then asked her if she was sure of what she was doing. She said yes and then took the gem from Eddie's hand. He then clasped her hand. When she was walking towards the portal of the Afterlife, Eddie heard a voice tell him to get the crown of the unknown ruler and use it to banish her from Nina. He quickly grabbed Senkhara's crown, said a spell that came to his mind because he was listening to the voice of the house and he then banished her out of Nina's body in order to save Nina's life. Eddie is willing to protect Nina at all costs. It seems coincidental that they are both international students from the United States of America. Eddie loses his Osirian powers in The Touchstone of Ra when he prevents Sophia from assembling the Pyramid of Ra and forcing a sacrifice for Ra.
Sarah Frobisher-Smythe, being a Chosen One, had to have an Osirian. Rufus was Sarah's protector, but instead the power went to his head, and he turned to the path of evil. He also made a deal with Victor to convince Sarah to sell the house. It is possible he lost his powers after Sarah died, but this is unknown.
Like the Paragon, the Osirian also has special powers. These powers include:
Mediumship: Eddie could see Senkhara in a dream.
Spirit Banishment: When Senkhara possessed Nina was about to enter Heaven, Eddie chanted a spell and pointed her own crown to her. This released a beam of light which forcibly pushed the spirit from Nina and into a flying cloud of black smoke.
Adviser: Eddie was told how to banish Senkhara by a voice in his head.
Eye of Horus: Both Nina and Eddie can use the Eye of Horus locket, but no one else can.
Visions: Both Nina and Eddie were known to have visions. Since Nina left Anubis house, the house communicates to Eddie through visions. He cannot control this and sometimes see what he doesn't want to see, though on a rare event, he managed to force a vision. Usually when Eddie has visions, it happens when he touches an object.
The Staff of Osiris: Eddie can put the Staff of Osiris together.
- There is no Osirian anymore because Eddie lost his powers in the Touchstone of Ra
- It's also a 50% chance that the Osirian could be replaced, giving a hint that in season 2 finale Senkhara told Nina she could be replaced, meaning it's possible that the Osirian can be replaced as well.
- The Osirian can replace the Chosen One in times of trouble.
- As the Osirian shares many powers of The Paragon, it is possible that they may be able to build The Cup Of Ankh and wear the Mask Of Anubis, same as the Paragon, but it is unknown, as Rufus could not do either, being an Osirian.