Complex sentence: Harry Wells, Cisco Ramon, and Caitlin Snow develop a serum to separate the Firestorm matrix from Martin Stein and Jefferson Jackson; however, Jefferson is reluctant to give up being Firestorm.
Split into simpler sentences: Harry Wells, Cisco Ramon, and Caitlin Snow develop a serum to separate the Firestorm matrix from Martin Stein and Jefferson Jackson. However, Jefferson is reluctant to give up being Firestorm.