Complex sentence: In order to lift it, Aeron must use the Oraclos Chain to obtain the flesh of the beasts that live in the 13 Towers of the Scar; if he does not complete this in time, Elena will gradually turn into a beast herself and perish.
Split into simpler sentences: In order to lift it, Aeron must use the Oraclos Chain to obtain the flesh of the beasts that live in the 13 Towers. If not, Elena will gradually turn into a beast herself and perish.