Throughout the series, there is a great deal of blood and gore, graphic violence as well as psychological violence. One of the most prevalent motifs of the series is the humanity of the Diclonius, especially contrasted against the inhumanity of ordinary people. One reviewer described the series as "devoted to quite a few of the darker, more callous factors of human nature." Throughout the series there are various incidences of casual beatings, cruel experimentation, and outright killing. Also, animal cruelty is present when three young boys mercilessly beat Lucy's puppy until it dies; though the act is off-screen, a copious amount of blood is shown; which drives Lucy to murder the bullies out of revenge and insanity.