Because Mir-Susne-Hum's mother, Kaltes-Ekwa, was defeated by her husband in heaven, this meant that Mir-Susne-Hum had to be born on earth. His antagonist was Jelping-Ja-Oyka.
Given that Kaltes-Ekwa's defeat in the spiritual realm necessitated Mir-Susne-Hum's terrestrial birth, his arch-rival emerged as Jelping-Ja-Oyka.