"You...you fool! Don't you know who I am?" The ugly thing with the fishbowl helmet shouted at the girl who held him at sword point. They were surrounded by Marines, though they had not moved in to aid him yet. "I am far greater than you!"
"We are equals." Satsuki Kiryuin told him. "No, I am far better than you since you seem to forget how to fight and who I am."
The Celestial Dragon looked up at her. "Wait a minute, you're..."
When Satsuki Kiryuin was five years old, she saw beyond the helmet the Celestial Dragons wore, and she was disgusted. Outside of her family, the other Celestial Dragons formed the Marines who would keep the world on a tight leash, yet their selfish desire for slavery and killing ensured that the worst pirates would keep their jobs. Entire towns, nations even, suffered from corrupted marines or these pirates, and these Celestial Dragons hardly bothered to do their duty. In fact, they spend most of their time travelling and shooting anyone in the way.
When Satsuki was near the age of 11, other children were old enough to enlist in the Marines. Satsuki had walked up to Sengoku and demanded to enroll in the Marine.
"But Lady Kiryuin, Celestial Dragons should not have to join the Marines." Sengoku reminded her. "You can command a fleet with your words alone."
"Funny how this seems to be the only rule the Celestial Dragons follow. Well, if the Marines forbid slavery and the Celestial Dragons break that rule, then I suppose it's fair that I break this rule too." And with that, Satsuki Kiryuin tore off her helmet and smashed it under her feet.
After that, the newly nicknamed "Fallen Angel" rose quickly through the ranks of the Marines, though as records would indicate, she did earn high marks. By the age of 12, she had already become a Captain, and by age 13, she became eligible to command a fleet. However, she had demoted the captains that the Marines chose for her, and she spent the next two years looking for more captains. Eventually, four new captains were selected by her hands: Nonon and Gamagoori were selected from the ranks of the Marines, though the other two were pirates; Houka was an information gatherer and Uzu previously led a band of 500. By the age of 15, she had already made plans to turn an island into another Marine base, this one under her command.
It was ironic that her actions, which abandoned the path of a Celestial Dragon, would mistakenly prove the "powerful" nature of the nobles. Sadly, she still had to be courteous to them, especially to her mother who did not raise a commotion about her joining the Marines. Once the pieces were in place, though, that was when she could strike.
However, plans do change. The Marine decided that destroying the lost son of Gol D. Roger would end the pirate age or something like that. Instead, this sparked a great battle that led not only to a power shift in the pirate factions but also the death of Roger's son, which would fuel his "brothers" to become stronger. The fact that his brothers were Sabo of the Revolutionary Army and Luffy of the Strawhat Pirates would make things worse.
To be truthful, Satsuki was still at her new base when the call for reinforcements came, but she hoped to use this opportunity to also turn the Marines on its head. However, Shanks had arrived and stopped further bloodshed, and despite what she thought of the pirate, Satsuki knew she missed the opportunity and stayed her hand.
At age 18, she received news that would change her life.
"Doflamingo has the String-String Fruit power?" Satsuki wondered. She was well aware of the fruit's power, given the fact that Ragyo has shown a mastery of strings. This also meant, given the nature of Devil Fruits, that it should have been impossible for Ragyo and Doflamingo to share the same powers unless they were nearly-identical powers.
"Yes, he has been hiding his powers for whatever reason. We managed to get that piece of information after he resigned..." He checked the snail. "...unless I'm mistaken since he's saying he did not give up his position."
"It was no mistake." Satsuki concluded. "He wanted to trap his targets, so he purposely falsified that information."
"But for Doflamingo to manipulate information at that level..." Uzu trailed off.
"He is a Celestial Dragon after all." Satsuki informed them. "Regardless of who he's targeting, Doflamingo has a power that should not be in his hands. We will have to investigate nevertheless."
Her four captains understood. Doflamingo was not going to be a threat. He was simply practice. No one said it would be an easy practice, but with the suspicions of identical fruit powers, they have an excuse to form a strategy.
And so, they sailed out towards Dressrosa. However, it was not just a conspiracy they would find.
((Spoiler: Ryuko may appear later if this was a story. Or possible earlier if she could be a pirate.))