The Beholder

The Observer (観察者) is Fushi's creator and the narrator of To Your Eternity.

Appearance
The Observer has light colored skin and wears a long, black cloak with a hood. He also doesn't appear to have hair.

Background
Not much is known about this mysterious being, but it has been revealed that he created Fushi in order to collect information and protect the world. The Observer also revealed that he is not immortal and will one day die.

Abilities
The Observer has the ability to sense the Knockers and know where they are (except for when they are underground). He compares it to the feeling of bugs crawling on your skin. "As eggs, you cannot notice them, but once they hatch, you are subject to great unease." The Observer is also strong enough to control Fushi, as seen in chapter 32 when he forces Fushi to transform from the boys form into a wolf. Although he can control Fushi's body, he cannot control his mind.
 * Detecting the Knockers
 * Controlling Fushi

Trivia

 * Although Fushi is normally the only one that can see and communicate with him, The Observer seems to be able to show himself/talk to other people as well. This can be seen in chapter 54 when Pioran asks The Observer to take her and, if possible, let her be reborn into something that can help Fushi.
 * The Observer hides many things from Fushi, including things about Fushi's abilities (being able to resurrect the dead) and the Knocker's whereabouts (ex: He failed to mention to Fushi that the Knocker was in Hisame's arm)