Devilman - Volume 1: The Birth(1987)

Overview:

Akira Fudo is just a normal kid in Tokyo, until an old friend of his, Ryo, shows up and turns his world upside down. An upcoming war of demons on humanity is waiting in the wings, however, the only way for a human to fight a demon is with their power. To save the world, Akira and Ryo risk a dangerous ceremony in an attempt to create humanity's only hope: the powerful Devilman.