Complex sentence: To their surprise, it works, and Penny gains superhero powers such as strength, flight, and the ability to pass through solid objects, to become, in Mike's words, "the world's most amazing 13-year-old".
Split into simpler sentences: To their surprise, it works, and Penny gains superhero powers such as strength, flight, and the ability to pass through solid objects. Penny becomes, in Mike's words, "the world's most amazing 13-year-old".