Rise of the Fallen Kingdom's Third Prince

Briols do not abandon honor. The unruly third prince of the Briol Kingdom, Yuri, manages to survive all by himself by escaping in the last moments of the kingdom's fall. After meeting his end while wandering in guilt, Yuri wakes up again to see his father's familiar face... He thought both he and the king had landed right in hell together. "Father, so in the end, you fell into hell too..." "What?" "Ah, well. That's to be expected from someone who always spoke about honor yet lived an indulgent life..." "What nonsense are you spouting?!" But he didn't go to hell, he regressed to the spring of his 13th year. One harrowing regret is enough. The kingdom shall be saved from ruin!

(Source: Kakao Entertainment Corp., translated)