Complex sentence: Despite being arrested by the Insurgency Batman, the Joker is freed by Harley, only to be defeated by the alternate Lex Luthor and taken back to the primary universe by the prime Batman.
Split into simpler sentences: Despite being arrested by the Insurgency Batman, the Joker is freed by Harley. The alternate Lex Luthor later defeats the Joker, who is taken back to the primary universe by the prime Batman.