Klaus is an Original Vampire, possessing immense strength, speed, and hearing. On the surface, he is cruel, short-tempered, narcissistic, and manipulative. He can be sadistic and ill-mannered, using his power to intimidate others. However, beneath this cold exterior, Klaus is deeply emotional, compassionate, sensitive, and passionate. He shows his love in a unique, all-consuming way, becoming incredibly soft and attentive to those he cares for. Much of his cruelty is a facade to hide a profound fear of being alone and to mask the guilt and remorse he feels for his actions.