Human who loved Midoriko

The is a manga only character.

History
He was a man who secretly loved the ancient priestess Midoriko hundreds of years before the events of the series, during the Heian Period of Japan.

Many minor yōkai (dragons, ground-spiders, oni, etc) possessed this mortal man who desired Midoriko and formed into one yōkai in order to kill her, similar to how Onigumo loved Kikyō and created Naraku.

However, unlike to Naraku, this result was not an hanyō but a full demon completely devoid of human feelings. In fact, while Onigumo's deadly body was completely devoured by demons and his evil spirit used as their adhesive. Interestingly, the human who loved Midoriko was only incorporated on the base of the dragon's neck, where his head and right hand can only be seen.

Midoriko
Not much is known about Midoriko and the human's relationship, if they even had one, other than the fact that the human was in love with Midoriko.

Trivia

 * In episode 25 of The Final Act we can see a face on the demon's neck.