Complex sentence: During this time, Oliver discovers that he is the biological father to a nine year child named William with a former girlfriend, Samantha Clayton, complicating his relationship with Felicity, his duty as Green Arrow, and threatens to jeopardize his mayoral campaign.
Split into simpler sentences: During this time, Oliver discovers that he is the biological father to a nine year child named William with a former girlfriend, Samantha Clayton. This discovery complicates his relationship with Felicity and his duty as Green Arrow, as well as threatens to jeopardize his mayoral campaign.