The Peasant Groom is the Abyss

Having vanquished a terrifying monster, a young warrior returns home under a dreadful curse that threatens to obliterate the kingdom unless he marries his destined bride in time. Disguised as a lowly laborer, he approaches the girl he grew up loving, but she mocks his poverty and casts aside his sacred dragon ring to court a wealthy heir. While the court sneers at the penniless outcast, a noble princess notices his hidden strength as the heirloom unexpectedly reacts to her presence. Surrounded by arena battles and deadly palace conspiracies, the shunned fighter struggles to secure his true match before dark energies consume everything.