Complex sentence: Chase is the new Star City district attorney who helps Oliver Queen as mayor clean up the streets through the legal system, while Prometheus is a ruthless and mysterious hooded archer who kills, and has a grudge against the Green Arrow and is aware of his identity.
Split into simpler sentences: Chase is the new Star City district attorney who helps Oliver Queen as mayor clean up the streets through the legal system. As Prometheus, he is a ruthless hooded archer who kills, and has a grudge against the Green Arrow and is aware of his identity.