Rena D. Stryder is a pirate captain of the crew Ghost Wake Pirates. She was once a Marine who had started from the rank of 'Seaman Recruit' to the prestigious position of 'Marine Captain'. She had joined the Marines at the age of 17 because she believed they were the way to change the world, having no prior knowledge of the many atrocities, questionable, and horrible actions of the Marines' higher ups, the World Government, and the Celestial Dragons. Before all this, she had trained for 10 years when she had first figured out what path she'd wanted to take in the world. She felt amazing at having achieved so much at such a young age until her illusion of righteousness of the Marines shattered. Rena then discovered that all the organizations and those she had looked up to when she had been a mere child and when she had been a lower ranked Marine had done more than enough to cause a lot of the hatred and violence that currently filled the world.
When she'd discovered this during several missions, she was of a mind to abandon the Marines and become those she'd once fought with all her strength, only, unlike many of the pirates she'd fought and captured or killed, she would try to be as morally righteous as she once thought the governmental organizations to be. She, as a Marine captain, journeyed to Water 7 to commission a smaller than average special "Marine" ship. Once done, Rena left the Grand Line under the pretense of doing a series of special missions while in actuality, she was gathering a small but strong crew to gather at the entrance of the Grand Line, the Twin Cape.
Her dream was the same, but she also wished to find and befriend the Straw Hat Pirates and aid them, for they were one of few pirate crews who did not fit the stereotype.