Complex sentence: While trying to prey on a nearby rat, Karai is trapped by Rocksteady and Bebop and presented to Shredder, who vows to Karai to cure her of her mutated state.
Split into simpler sentences: While trying to prey on a nearby rat, Karai is trapped by Rocksteady and Bebop. Upon Rocksteady and Bebop presenting Karai to Shredder, he vows to Karai to cure her of her mutated state.