Because the party automatically loses when Banon is KO'd, the trick is to kill Ultros before he attacks Banon, although if Banon is of a high enough level and/or in the back row, he can survive Ultros' Tentacle in which case the battle is easy. In the GBA version of this fight, Ultros will counter all offensive magical attacks with Ink, which damages and has a chance to Blind the party. This reduces Terra's effectiveness as an attacker in this fight.