Goro

Goro (齩郎) was the vessel that Satan possessed before the Blue Night took place.

Appearance
Goro appears almost identical to Shiro Fujimoto, due to them both being clones of Azazel.

Personality
Being a clone body raised through the use of experimental Elixir research, Goro's personality should have failed to develop properly, according to Mephisto. He was seemingly capable of speech at one point, but by his teenage years, he had lost his mind due to experimentation, leaving him in a near vegetative state.

Blue Night Investigation arc
After being pulled out of Section 13 by Mephisto, he begins to explain the history of the laboratory to Lewin Light and Ryuji Suguro. He tells them during their experiments to make a suitable vessel for Lucifer, one of the clones was possessed by an initially unknown entity. Eventually they concluded that the entity in question was Satan himself. The Blue Night then took place not long afterwards.

While pouring through all of the laboratory's records, Ryuji finds a missing section of information on a clone named Goro. He immediately tells Lewin as he believes that Goro is the vessel Satan possessed that Mephisto told them about.

Blue Night Remembrance arc
Shiro encountered Goro again during his yearly experimentation, but by this time, Goro's mind had deteriorated to the point of near vegetative. Some time after this, whilst being administered an Elixir, Satan first tried to possess Goro, but failed to take hold. It would be a further nine years before Satan properly took control of Goro's body.

Goro's body was finally destroyed by Lucifer at the beginning to the Blue Night.

Trivia

 * Despite he and his fellow clones having a distinctly number based naming theme, Shiro being Four, Goro being Five, and Rokuro being Six, their names do not contain the kanji for these numbers, instead being homophones with the same pronunciation.