Elixir

The Immortality Elixir are a series of experiments carried out by the Illuminati in an attempt to maintain Lucifer's failing body and later to create a body capable of surviving possession by Satan.

Elixir #51
Elixir #51 was developed during the Section 13 years of experimentation by Nikolae Eminescu. Taking blood from fifty-nine demons with powerful regenerative abilities, it was injected into dead mice and human flesh. Taking blood from samples showing arrested necrosis, it was applied to the entire Lucifer test group. Of this group, eleven showed heightened cellular regeneration. From this group, cells were extracted and refined to produce this elixir. It ultimately proved ineffective.

Elixir #97
Elixir #97 was used during experimentation on Goro when Satan first attempted to possess him.

Elixir #1021
Elixir #1021 was the first new substance created through the experiments on Tamamo Kamiki. One of the many immortality elixirs created by the Far East Laboratory, if it had worked correctly, it would bestow immortality. However, if not, it would attack the central nervous system and slowly turn bodily tissue necrotic. It was originally tested on Maria Yoshida.

Elixir #1117
Elixir #1117 was one of the later developments in the pursuit of the Immortality Elixir. While it did not achieve the desired result, it did serve to sustain Lucifer's body without degradation or necrosis. It was later used in the Illuminati's final experiment on their Chosen Ones.

Completed Elixir
The Completed Elixir was created in the final experiment by the Illuminati in order to create Satan's perfect vessel. By repeatedly performing elixir experimentation on Demon Eaters, those that grew strong enough to withstand possession by Ouroboros, Phoenix and Hydra type demons without losing their faculties were considered Chosen Ones. These chosen ones were then burnt alive in a Distillation Furnance until only a handful of carbonized cells remained and were doused in Elixir 1117. The rest of the process is unseen, but Egyn is ultimately able to only secure one drop of the completed elixir. This proves to be enough to complete Satan's vessel as after injecting it into a clone of Azazel provided by Drac Dragulescu, Satan possesses the vessel with no apparent ill effect.

Trivia

 * The Elixir of life is often considered a key goal of Alchemy and appears in myth and stories throughout history.