Pokemon Phoenix Red

Pokémon Phoenix Red takes place approximately 20 years after the Great War between Kanto and Johto, in which Red and Blue did not survive. You are the protagonist playing as Red's child, starting your Pokémon journey alongside your rival/Blue's son. Lance has fallen as the Champion of Kanto and Johto after many years of peace between the regions. Tensions are now at a boiling point, and the two regions appear to be heading toward another war. Without Kanto's greatest heroes to save the day, it's up to you or your rival to rise to the challenge, become Champion, and restore peace and stability.

Source: TheGamesDB