This character, place, item or organisation originated in the anime and has never appeared in any work considered part of the manga canon.
Narain is an indian boy who was best friends with Allen during Allen's stay in India. He became an akuma's vessel for his sister Mina.
Narain is a boy with spikey gingerish hair. He wears a shirt that exposes his belly.
When Allen and Cross had been in India at a royal palace of the Maharaja, Narain was working at the palace along with his sister, while studying to go into medicine, and he and Allen became friends.
After one particular training incident, a depressed Allen went to see Narain, However, he found him grieving because his sister had died, frustrated that there wasn’t a way in the medical books to bring his sister back, making him feel useless. This was perfect for the Millennium Earl, and Narain became an Akuma.
Allen initially couldn’t think of killing his friend, but Cross told Allen not to run away. He wanted Allen to fight and sever the chains of sorrow that bound Narain’s sister’s soul to the Akuma. After Allen successfully activated his arm and destroyed the Akuma, he found the experience painful, and Cross told him to get used to it, and to harden his heart to such pain in order to make it as an Exorcist.