Simply known as "Master", he is the sole reason that Palna absolutely despises demons. They became close friends when Palna was younger and he taught her many things. He was an extremely gifted young scholar and had a dream to create a world where humans and demons could live together in coexistence. 

He has endless positivity and optimism, and no matter how many times he's turned away or shut out from the demons, he never waivers in his goal, until he's finally even able to win over an entire tribe. Palna looked up to him and he had a knack of making everyone around him not only listen, but believe in his dreams.

He is later killed at the end of the flashback in a horrific massacre, destroying the dream he had worked so hard to build.

I picture his voice being a bit on the medium-higher teenage voice, with a more intellectual but extremely positive energy to it.