Raiden's "Jack the Ripper" Persona is the Player
During the raid in Denver, Raiden is tormented by Jetstream Sam. His "one sword keeps another in the sheath" logic is put against his actions, revealing the suppressed fears of the soldiers he's been killing. Raiden becomes ashamed and conflicted, weakened similar to when he lost his arm in Africa - Sam has disarmed him again. Then he meets Monsoon, who taunts him for his ruthless killing by suggesting he must enjoy it.This is a throwback to Metal Gear Solid, where Liquid accused Snake of enjoying killing and Snake denied it. On a meta level, killing is why the player is playing the game; shooting fictional people in a fictional world is fun. The confrontation puts the player's desires at odds with Snake's - the player likes killing, but Snake doesn't. This isn't quite Ludonarrative Dissonance because while Snake doesn't enjoy killing, it's all he knows and it's the only way he feels alive, so he'll never stop. This is because he's a video game character who exists only to fight.
However, Rising: Revengeance takes a different route because Raiden doesn't deny that he enjoys killing. Instead, Raiden's "Jack the Ripper" persona comes out. He rescinds his statement that his sword is a "tool of justice", coming to the conclusion that he's always loved killing and that justice was his excuse to do so. Rather than contradict the player like Snake, Raiden succumbs to the player. You are Jack the Ripper. Raiden accepts that you are playing this game to face a challenge, and you don't really care about bringing Desperado to justice. The game doesn't try to guilt-trip you about it, instead telling you to let it all out and go crazy! It even gives Raiden a new super mode mechanic that encourages brutality. This is a hack 'n' slash game about cutting cyborgs into tiny pieces, and you're gonna play it this way no matter what, so go for it!
But this is not necessarily a victory. By succumbing to Jack the Ripper, Raiden falls back under the control of the player. He once escaped from the player to fight for his own memes at the end of Sons of Liberty, before getting stuck serving the Patriots for a while during Guns of the Patriots. Throughout the entire first half of Rising: Revengeance he has been slowly pulled back under the player's thumb, culminating in this moment where he succumbs once more.
Of course, Raiden's character arc isn't over here. At the climax, he accepts that his life has never been about justice nor the fun of killing, but rather because he pursues his goals no matter what. The player and Raiden come into harmony, as both of you fight Senator Armstrong simply to put an end to this conflict. Jack the Ripper - the player - doesn't dominate Raiden's psyche after all, but is merely a part of a more complex character. And in the ending, Raiden has escaped from the player's control once again to fight his own war, but leaves room in case they ever need to come back.
