English | Japanese

« What I'll become... will be too strange."
"To drink... or not to drink!? »


English | Japanese

« ... I came, I came I came I came I cameee! »


Dangerous Game: The Secret Game of Sin (密やかなる罪の遊戯
, Hisoyakanaru Tsumi no Yūgi
Denjarasu Gēmu
?) is the Noble Phantasm of Dr. Jekyll and Mr. Hyde, an elixir (miracle drug) that allows for the transformation of Jekyll into Hyde, the second personality inside the former's body that claimed so many victims in his life. It can also be used to revert the transformation, transforming Hyde back into Jekyll. The elixir was refined through pharmacy and alchemy as well as from an accidental result similar to degradation done over several years. It is an elixir that is impossible to reproduce with modern science, technology and magic.[1]

Under the Assassin class, drinking the potion allows for Jekyll to turn into Hyde with a nature close to a Berserker, but Hyde retains a humanoid form and with more reason than his Berserker-class counterpart. In the case of Hyde, he acquires close-combat power comparable to the Three Knight Classes, even being capable of overwhelming them.[2]

Under the Berserker class, upon drinking it, his form changes, becoming covered in black fur, his spine cracking, his muscles expanding, growing long canines and sharp claws, and his eyes becoming blood red, making him somewhat similar in appearance to a werewolf. In this form, his stamina greatly increases, as well as his strength and speed. He gains several skills that make him suitable for close quarters combat, most noticeably, a skill that he calls "Restructuring", which grants him a highly potent recovery ability, making him confident in that he can recover from being hit by even a Noble Phantasm.

The difference in transformation performed between being an Assassin and being a Berserker lies in his Self-Modification Skill. The Skill would be limited by the Assassin class. However, being summoned in the Berserker class would give rise to a cumulative effect of this Skill combined with Mad Enhancement, no doubt turning him into a beast that hardly resembled human.[1]


The miracle drug bottle design uses a rose motif.[1]


  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Fate/Grand Order material III - Dr. Jekyll and Mr. Hyde, p.072-081, translated by TwilightsCall at Beast's Lair.
  2. 2.0 2.1 2.2 2.3

Community content is available under CC-BY-SA unless otherwise noted.