While Enmaten was amalgamated with Enma-daio in China, the two were separately introduced into Japan, which might be the reason that the same was split into two.
中国では閻魔天が閻魔大王に習合されていたが、日本に伝わった時にそれぞれ別個に伝わったため同一存在が二つに分かれたとも考えられている。