Just like all the other Eternals, Kirby created him as a mixture of science fiction mixed with classic mythology.
[1][2] Like all other Eternals, Sunen was created by the Celestials around a million years ago on earth on early humanity.
Kingo spent centuries in Japan learning the ways of the Samurai, and is one of the most skilled swordsmen on the planet.
In the present day and age, he has parlayed his skills into becoming a major action film star in Japan.
[5] Kingo Sunen presumably has all the typical powers of Eternals—immortality, super-strength, flight, energy projection, and molecular manipulation.