Nina reveals to Tenma that she was the actual subject. When she returned to the "Three Frogs" apartment and told Johan what happened, he "became" her, adopting her trauma as his own to protect her or because he could no longer distinguish between them.
Monster Episode 67, titled is a pivotal moment in Naoki Urasawa’s psychological thriller, marking a massive shift as the series enters its final arc. This episode shatters what viewers thought they knew about the twins' traumatic past at the Red Rose Mansion. Episode Recap: The Identity Twist Watch Monster (Dub) Episode 67 for free on gogo...
For the entire series, Johan has acted as though he experienced the horrific eugenics experiment and the subsequent massacre of 46 people at the mansion. Nina reveals to Tenma that she was the actual subject