TALE OF THE COLD EMPEROR

Athan, a 16-year-old boy, lived until he was killed for a stupid reason. But it seems that fate had stored different things for him as after death as he transmigrated in the magical world inside a dead body of a boy with the same name and same facial features as him. He also found out that a mysterious black whirlpool seemed to be inside him. Was someone responsible for his transmigration? if so then who? and why? or was it pure coincidence that he got a new chance at life?