Narse is a titan, which in my creative universe is a sort of primordial elemental god. He controls the shadows cast by Sol that fall upon the Earth, and is associated with night and sleep. He created the first shadow-beasts and they all pay homage to him. He is said to reside inside the hollow Darkside Moon which gives that dimension its light, sleeping as shown here.

His avatar looks the same as this, with indigo blue skin, hair and eyes. His true body is too vastly enormous to be practical to interact with on a human level.