Metroid Fusion

Metroid Fusion begins with bounty hunter Samus Aran guarding a research team on the planet SR388, where a yellow parasitic organism — later named X — emerges from a creature she kills and infects her body. Feeling fine at first, Samus completes the job, but soon collapses, and her gunship crashes; her escape pod saves her, though the ship is destroyed. Doctors discover the X parasite buried in her nervous system, give her less than a one-percent chance of survival, and are forced to surgically remove large portions of her infected Power Suit, drastically changing its look. Their only cure is a vaccine made from a cell of the Baby Metroid that once saved Samus — the Metroids being the X's sole natural predator. The serum wipes out the X in her body, but leaves her able to absorb X to replenish health and ammo, while inheriting the Metroids' fatal weakness to cold. Recovered, Samus is sent to investigate an explosion aboard the Biologic Space Laboratories station, where the SR388 specimens and her infected suit pieces are held. There, guided by her ship's computer — which she nicknames "Adam" after a former commanding officer — she learns the X have overrun the station and can perfectly copy the DNA of anything they infect. Worse, they have used her discarded suit to create the SA-X: a duplicate of Samus with all of her fully upgraded powers, which releases the captured X specimens across the station. Samus also uncovers a secret Federation program illegally breeding Metroids, and discovers there are now at least ten SA-X copies hunting her. When the Federation orders her to stand down so it can study the X for its own ends, Samus — having seen the SA-X's destructive power firsthand — refuses, certain the X would absorb the troops and spread across the galaxy. Instead she resolves to crash the station into SR388, destroying the X for good. Realizing her ship's computer truly carries the uploaded personality of Adam Malkovich, who died saving her, she wins its help, survives a final battle against an SA-X and a fully grown Omega Metroid — saved at the last moment when an SA-X turns on the Metroid — and reclaims her lost abilities. As she escapes, the station plunges into SR388, annihilating both the planet and the last of the X. Reflecting that few will ever understand what she prevented, Samus takes comfort in Adam's words: "One of them will understand. One of them must."