These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Complete Monster: Jack the Ripper. During his original killing spree, he used his victims' wombs in a potion to grant him immortality. Initially he felt remorse over his first murder, but he immediately embraced his enjoyment of killing (as otherwise the spell wouldn’t work). About half a century later, the effects of the potion are wearing off, so Jack continues killing and mutilating several prostitutes. Jack meets the Monster, who had befriended some of the women. As the Monster desperately tries to save Jack's dying victim, Jack taunts him. Discovering the Monster's near-indestructible body, he kidnaps Dr. Frankenstein's wife Elizabeth and holds her hostage to force Frankenstein to create him a new body like that, so he can live forever. He also stabs a man who tries to expose him, cuts off the foot of Frankenstein's best friend and leaves it as a "souvenir" to give Frankenstein a ransom note written in blood. Out of any character in the Frankenstein series, Jack the Ripper truly is a monster.