Kaito Tenjou

Kaito Tenjou is a Number Hunter in Yu-Gi-Oh! ZEXAL. He was originally a nice person, but when his brother Haruto Tenjo fell sick, Dr. Faker told him that it was due to the Number holders and the Astral World, thus Kaito turned evil trying to seek out the holder of The Emperor's Key which would lead him to Astral.