Caek Sanorium

Caek Sanorium first appears in the prequel Seraph of the End: Guren Ichinose: Resurrection at Nineteen light novel story. He is a Fifth Progenitor among the vampires and works directly under Saitō's command. He was tasked to guide Guren to him, and fought Guren's squad to enable them to speak in private.

Appearance
He has a beautiful wavy brown hair and alabaster cheeks. According to him, his body has been altered. Like all true vampires, Caek has red eyes, fangs, and pointed ears. He wears the clothes of a noble, and like most vampires, he wears white clothing.

Personality
In keeping with other vampires, he has apathetic demeanour but can have polite manners, such as answering almost anything the enemy wants from him truthfully. Caek even complements Guren's strength. Even if treated badly he does not show any ill grudges. He never shouts in anger, and is always calm.

However, since he works under Saitō, he does what he is told from him and nothing more. He shows emotions of his own will also, for instance he would not hesitate to drink the blood of others as vampires are generally wanton to do.

Events of 2013
Caek does nothing but awaits Guren arrival with his squad, whom they were on a mission to restore the power in the city. With Guren and Shinya reaching him, Guren's sword clashed with Caek's and he greets Guren. Guren knew Caek was strong as a noble before he is attacked by Shinya three times using Byakomaru, then Caek informs the latter he already knew Shinya's location.

He then grabs Guren by the collar when Guren tried to leap back, and raises him bodily into the air. Caek almost chokes Guren if not for Shinya's aid using Byakomaru to distract him. Smirking and sounding amused, despite a vampire's apathetic nature, Caek still carries Guren with him, easily overpowering the duo. He complements Guren's strength such as they are inhumane, hardly believing he is human.

With Guren wanting him to identify himself, Caek informs Guren that he is a fifth progenitor and a high ranking noble, then remarks his body has been altered as well. Guren warns Shinya to stay back, as his rank is high, which makes him dangerous. As he is still holding Guren by the collar, Caek asks him again who is he, then if Guren wants to know his name having identified him as Guren Ichinose as he already knew Guren.

When asked his name, Caek provides it to which Guren claims he never met him him nor heard of him and wants to know what does he want from him. Caek gives him an answer which his master has taken a 'shine' on him, referring to him as Rígr Stafford when Guren inquires about his master. He makes him easier to understand by giving him the name Guren knew which is Saitō.

Caek is grabbed by the shoulder by Guren, questioning him if he is after Mahiru, yet Caek knows nothing of her, however Guren does not believe him. Caek assures him he is not lying as he barely know anything of Saitō's plans, which he himself does not understand. Continuing to be questioned as to why he is here, before he could give an answer, Shinya arrives at his location shouting for Guren. Shinya had his rifle ready to shoot Caek, which would not faze him and he could easily kill Shinya.

To prevent Shinya's death, Guren lies to him that it is all over for him. When the power station is turned on, Caek was puzzled remarking that it's strange. Later, Guren's friends arrive, and Guren tried to wrap up their conversation with Caek. He is informed by him that there is nothing more to talk about as his mission is done and he was ordered not to harm his friends, but mentions he might drink a little of their blood.

Now facing Shinya, Norito, Mito, Shigure and Sayuri, all five of them have not made a dent on him, but according to Shinya he does not seem set on killing them, however he has been holding back, since he could kill them all if he wanted to. It is revealed his mission was only to delay Guren's friends while Guren finishes his conversation with Saitō.

Guren and Shinya plan on dashing away from him, however Caek leaves Guren's friends tired as he drank so much of their blood, and it is revealed that Caek has already left having completed his mission.

Saitō
Caek considers Saitō to be his master, and he obeys him without question. He was sent by him to meet Guren Ichinose, and apparently fight him to test his strength. According to Caek he understand very little of him, and everything he does doesn't make any sense to him. He refer to him as Rígr Stafford.

Natural abilities
As a vampire, Caek is naturally far stronger and powerful than any human, plus he has immortality. Being a fifth progenitor, he is one of the strongest vampires with immense strength. He was able to overwhelm Guren and Shinya completely when they first met, having the upper hand in the whole fight. He could have killed all of Guren friends if he was ordered to, none of them managed to wound him, not even Guren or Shinya attacks.

As a noble, he also has permission and the ability to turn someone into a vampire if he so chooses to.

Weapon
Caek wields a first-class vampire sword, although the true strength of his sword is not revealed, when he blocked Guren's strike, a huge clash sounded in the atmosphere.