Complex sentence: During the "Crisis on Earth-X" crossover, an Earth-X version of Winn is introduced; he is the leader of the Freedom Fighters working against the New Reich on his world and thus is Dark Arrow's enemy.
Split into simpler sentences: During the "Crisis on Earth-X" crossover, an Earth-X version of Winn is introduced. He is the leader of the Freedom Fighters working against the New Reich on his world and thus is Dark Arrow's enemy.