Beautifully written episode. Had the futuristic steampunk vibe. Felt like an episode of Warrior story wise, with the Chinese immigrants arriving to seek fortune and work, eventually forming the largest Chinatown in America and playing a crucial role in shaping the city's culture and economy.
This one is a bit tough to watch and is undoubtably very disturbing hence the title, NOT FOR EVERYONE.
Personally I love characters undergo a physical metamorphosis to become something unstoppable. This is especially interesting when the character has suffered so much and that suffering leads to their transformation.
This is why characters like Wolverine from X-Men or Griffith from Berserk are incredibly popular. It just makes for a stronger character.
Having said that, this episode is about the moments leading up to the creation of an epic vigilante. While it is incredibly depraved, it's worth a watch if you are up for it. I seriously wish this could've been a full length movie or series. It would definitely be neat to watch.