In his youth he set out on a quest to become the worlds greatest Eidolon trainer. His adventures led him to a ruined city, and with the help of his loyal friends. He helped rebuild it into a thriving metropolis.
In the ruins of the city, Ash found a great arena. Which he then used to found the EDC (Eidolon Death Colosseum). Today that city has become the Mecca of summoners the world over. No summoner is considered to be truly great until they have had a round in that Colosseum.