I finished this over a few weeks ago, and forgot to post These are my interpretations of human Raava and Vaatu designs. Both are the spirits of Light and Dark, Raava is the Spirit that merged with Wan and made the First Avatar. Vaatu is currently trapped in a tree after their battle over power ended in Wan and Raava winning. These are from The Legend of Korra.
Raava and Vaatu(c) Their owners
Art and designs(c) Strawberrytop007