Why am I just realizing Shanks might actually be inspired from Thor???
"Fierce-eyed, red-haired. God associated with lightning, thunder, storms, sacred groves and trees, strength, the protection of mankind, hallowing, and fertility."
The possibility of Imu to be an immortal & an actual celestial being aligns with Cthulhu. Similar archenemy concept as in Ben 10 and also the conflict between the celestial beings & the natives, mostly the D clan along with the extinct races from Void Century.