Complex sentence: Aslan returns to life by Deeper Magic-which states that death will reverse if a willing victim who has committed no sin is slain on the table -, and in the subsequent battle, Aslan kills the witch, ending her reign of terror.
Split into simpler sentences: Aslan returns to life by Deeper Magic, which states that death will be reversed if a willing victim who has committed no sin is slain on the table. In the subsequent battle, Aslan kills the witch, ending her reign of terror.