Complex sentence: Despite the fact that she defeats Rex Tyler's killer and gains knowledge of her future destiny, Amaya decides to remain with the Legends and her new relationship with Nate, reasoning that she can return to 1942 and her destiny at any point.
Split into simpler sentences: Despite the fact that she defeats Rex's killer and gains knowledge of her future destiny, Amaya decides to remain with the Legends and her new relationship with Nate. She reasons that she can return to 1942 and her destiny, which she opts not to change, at any point.