If Sniper Wolf is Mistral's analogue in Revengeance, Psycho Mantis is no doubt Monsoon's. This one seems less intentional however, but it is a strong correlation nonetheless. Again though, in Revengeance the antagonists are painted in a far more black and white manner, so the resolve Monsoon exhibits seems to be more absolute than what Mantis displayed.
The strongest feature the two share is no doubt their worldview. Monsoon's dialouge even echos Mantis's with the only difference being the former's following statements occur before the battle while the latter's occurs after:
Monsoon: "Kill or be killed, Jack. Phnom Penh taught me that. Yes, you aren't the only one who grew up on the killing fields. War is a cruel parent, but an effective teacher. Its final lesson is carved deep into my psyche: That this world, and all its people, are diseased. We are all pawns controlled by something greater: Memes. The DNA of the soul. they shape our will. They are the culture - they are everything we pass on. Expose someone to anger long enough, they will learn to hate. They become a carrier. Envy, greed, despair...All memes. All passed along. ----I've misjudged you, you are like us after all."Also to consider:
Mantis: "But you... you are different... You're the same as us. We have no past, no future. We live in the moment. That's our only purpose. Humans weren't designed to bring each other happiness. From the moment we're thrown into this world, we're fated to bring each other nothing but pain and misery.----We are truly the same, you and I... The world is a more interesting place with people like you in it... I never agreed with the Boss's revolution. His dreams of world conquest do not interest me. I just wanted an excuse to kill as many people as I could. ----I've seen true evil. You Snake. You're just like the Boss... No, you're worse. Compared to you, I'm not so bad."
Both are Bridges
Both characters serve as a bridge between the protagonist and their own monstrous side. Mantis is described as a 'parasite' and monster---his sole aim is shown to have been simply to get inside Snake's head and cause as much chaos as he could. Monsoon is no different in how he approached Raiden, though he seemed to specifically focus into drawing out Raiden's childhood horrors for his own amusement. It ends up biting them both in the ass however, though they express an almost preemptive acceptance of their own deaths, which leads to the next point...
Both characters refute any value in human life, including their own, so even when they're struck down, it's more of a fact of life in their eyes than it is some great loss they have suffered. They both accept it immediately and willingly. Doug Stone's voice acting for Mantis implies mild amusement in the PSX version while Monsoon expresses a melancholy yet trenchant statement of Raiden having accepted what he is. He passes away the victor and the player is granted access to the game's 'Ripper Mode'.
"Blackout!" & "Lorentz force, Go!"
Both battles revolve around the player having to dodge a numerous amount of inanimate objects being thrown at them by these two aggressors. While Mantis is only throwing paintings and statues however, Monsoon is (in Platinum style), throwing shit such as cars, tanks, and helicopters---things that weigh well over a ton. Psycho Mantis seems to rely on a general form of psychokinesis, whereas Monsoon's ability is stated outright to be the result of his magnetized cyberization.
Physique of the Pestilential
Both are thin, gangly figures with a mask obscuring the majority of their face, and they're both masks you will probably want to keep on their heads as well. Mantis has a deformed and mutilated face while Monsoon has cyberized his own body right down to the skull and eyes, which seem to be able to protrude from their sockets and swivel around (not to mention a mechanic of his fight involves his head flying off entirely and the player having to chase the damn thing around).
"That was cool...and annoying."
For Mantis this was the whole Kojima fuckery sort of first getting its limelight in 1998. He read your memory card, told you what you played, and did weird offbeat crap that involved you having to switch controller ports on your Playstation console. There's a couple of ways to take care of Mantis as well, given that he throws a lot of these off-the-wall things at you. He shares his legacy with Monsoon in that he keeps the player guessing (at least during their first playthrough anyway), leaving them to spend 75% of the fight just figuring them the hell out.
For Monsoon, it's his general aesthetic and how that blended into the actual gameplay of his fight. Most notable is the fact his entire body is segmented. Where every other fight in Revengeance is a straight up slash battle, Monsoon's is a segmented war of attrition. You spent the majority of the fight on an extreme edge learning how to counter every move he throws at you, rather than any kind of straight attack. Doing so will cause his body to magnetize and separate which leaves him essentially invulnerable. Generally if you ask people who they had trouble with in the game, nine times out of ten they will say Monsoon (followed by Armstrong).
Given how much the two have in common, I find it hard to believe Mantis wasn't in the development's mind when designing Monsoon, but it's a nice to have this link up with one of my favorite games of all time, as it lets me enjoy the game in a sort of backdoor manner. I sure as hell couldn't get in through the front.
1. Monsoon - Metal Gear: Wikia [Link]
2. Image: [Link]