Complex sentence: Eventually Marche succeeds in his quest to return Ivalice to normal, teaching the other children in the process that they cannot live in fantasy but must learn to live with their misfortunes in reality.
Split into simpler sentences: Eventually Marche succeeds in his quest to return Ivalice to normal. He teaches the other children in the process that they cannot live in fantasy but must learn to live with their misfortunes in reality.