The Russian Reversal between Samus and the Metroids, and their growing similarities.
Let's examine their relationship through symbolic terms in a Cain and Abel situation first:
Now, Samus and the Metroids are obviously Not Blood Siblings, hell they're not even the same species, but there is a reason why that trope exist, I meant in a more abstract but to my eyes still valid sense. I meant a situation and narrative similar to the Human/Forerunner conflict in Halo where both sides are Science Projects of Sufficiently Advanced Alien Precursors fighting each other until one proves superior which is pretty much what happens in Metroid. Both the Metroids and Samus were science projects designed by the Chozo to protect the Galaxy from threats the Chozo couldn't deal with themselves: The former the X parasites, the later everything else (Implied to include the Metroids themselves after they outlived their usefulness and became a threat which if true, it meant the Chozo were aiming for this trope) Family of Choice is a very important trope in Samus's story and I feel that both being creations of the Chozo gave me a sense of Sibling Rivalry There Can Only Be One vibe for the Metroid arc, even if, just for Irony, neither side ever knew it.
With that let's move to their growing similarities, shall we?
With Samus becoming part Metroid, something that makes at least young Metroids instinctively friendly towards her, and with her being pitted against an Evil Twin at her full power (Who makes a point of using the Metroid destroying formula: freeze ray, then Super Missile to the face) Metroid Fusion completely inverts the tipical situation for the series. After fighting metroids for so long, she has become one which fits very neatly into Nietzschiam wisdom. I see the SA-X having Samus's appearance and powers as Fate's idea of an ironic joke: Samus has to fight an evil and twisted image of her past self as one of the creatures she used to kill.
- Nietzsche: He Who Fights Monsters should see to it that he himself doesn't become a monster, for when you stare into the Abyss long enough, the Abyss stares back.
By the time of Dread, her Metroid DNA has started to awaken, slowly turning her into a Human form Metroid and giving her their Life Drinker abilities which (as mentioned in the game's Nightmare Fuel page) she uses those powers the exact same way as the metroids, culminating on her going absolutely feral on the Final Boss, who planned to use her as a bioweapon, just like both the Space Pirates and later the Federation did to Metroids. In fact, Samus's behavior slowly starts to become more Metroid like to the point where Eating the Enemy becomes a valid tactic, and I don't know about you, but if this was done by a villain of the series, far from cool, this would be horrifying, specially what she does at the Final Battle.
The Metroid incident Myth Arc seems to imply that while she's nothing like Space Pirates, she's Not So Different from the Metroids and leaves the implications of that to the player's imagination. The fact that Samus and the Metroids are sister projects of the Chozo makes things even weirder.
