Remnant

Remnant is a powerful, mysterious substance that is the physical manifestation of a spirit's emotion. Used as a serum of immortality and as a source of infinite energy, it is a major, pivotal part of the plot of BlueyCapsules.

So far, there are two known variants -- Dark Remnant and Light Remnant. Dark Remnant is a purple-pink color, while Light Remnant is bright yellow. Currently, the properties of Light Remnant are unknown.

It is created when a material inhabited by a spirit is burned or melted, and possesses incredible power, capable of making a person conditionally immortal. It is also capable of powering almost all forms of technology without depleting, and enhances the performance of electronics significantly. However, it is sensitive to heat and fire, and can be destroyed if overheated.

It was first discovered by William Afton after setting fire to the Puppet's severed arm. He later managed to obtain Dark Remnant from Chica the Chicken after the spirit of Susie Denver possessed it, and then from the other animatronics after they were possessed. William is studying the substance to discover it's properties, what it's capable of, and any possible uses for it. He is also trying to find ways to produce more, and this was a driving motive for the Missing Children Incident. Light Remnant has only been obtained from the burning of Sunny Afton's lamp vessel thus far, and not much research has been conducted on it as a result.

Vincent Afton was William's first human test subject, with Dark Remnant being injected directly into his bloodstream. William's theory of Remnant rendering a person immortal was proven correct after Vinny was shot in the neck by Gino Valentino, and was miraculously unaffected by it. Later, Scott Afton would also take the Remnant, and eventually William himself would take it as well. William would then go on to use the Remnant to power animatronics for Circus Baby's Pizza World and the new Freddy Fazbear's Pizzeria (1986) by using and melting parts from the older animatronics.

Characteristics

If injected directly into the bloodstream, it makes a person immortal (with fire/overheating being the only weakness). A person immortalized by remnant gains glowing white pupils.
Capable of powering most, if not all forms of technology, without depleting. Enhances performance of electronics significantly, but can be unpredictable.
Physical manifestation of the spirits’ emotions/pain, NOT fragments of the soul.
Created after burning a substance inhabited or influenced by a spirit.
Must be separated from fire/melting source immediately after creation to prevent destruction.
Begins to evaporate at around 150 degrees Fahrenheit (66 degrees Celsius).
If it has been too overheated it will lose its characteristic glow.
At the initial time of melting, it retains a semi-solid state with a consistency similar to cake batter. Over a period of roughly six hours, it reverts to a thinner liquid state, but does not appear to lose any properties.

Currently used in...

Immortalized people

Vincent Afton (injected by William Afton)
Scott Afton (injected himself)
William Afton (injected himself)

Technology

Used to power the Funtime animatronics and to create dangerous killing mechanics, and to extract more Remnant from captured children.
Used to power the facial recognition technology in the Toy animatronics. However, this mechanism was destroyed after it backfired against William/Dave.