In the beginning of the game, Basilio rules Ferox but he is dethroned when Chrom defeat his champion, Marth. He is replaced by the other khan, Flavia. He also gives away his best warrior, Lon´qu to Chrom.
Later on he is helping Chrom, prince of Ylisse against Ylisses enemies. Later when the Gangrel, king of the nation Plegia starts a war with Ylisse and kidnaps Emmeryn, exalt of Ylisse, Basilio agrees to help Chrom rescue her. The rescue fails however and Emmeryn dies, Basilio escapes together with Chrom and the rest of his group. Later, Emmeryn is avenged when Gangrel is defeated in battle with Chroms men and the war between Ylisse and Plegia ends.