Beyond is a highly intelligent and complex individual. He is also very ruthless and has no qualms about killing people. He believes that the only way to achieve a perfect world is to eliminate all evil, even if it means wiping out innocent people as well.
Beyond's reign of terror begins when he uses his Death Note to kill several criminals and police officers. He also begins to play a game with L, the world's greatest detective, by sending him cryptic messages and clues.
As L investigates the case, he begins to suspect that Beyond is the second Kira. He eventually tracks Beyond down and confronts him. However, Beyond is too clever for L and he manages to escape.
Beyond continues to kill people and evade capture for several more months. However, he eventually makes a mistake and L is able to trap him. L then uses his Death Note to kill Beyond, putting an end to his reign of terror.
Despite his evil actions, Beyond is a tragic character. He was a child prodigy who was abandoned by his parents. He grew up in an orphanage where he was abused and neglected. These experiences left him with a deep-seated hatred for humanity.
Beyond is a cautionary tale about the dangers of unchecked power. He is a reminder that even the most intelligent and capable people can be corrupted by their own desires.