Hey wait a second...
We can't be a phazon metroid. We were a juvenile metroid before phazon evolving. Phazon metroids grow from miniroids, which are baby metroids that are infused with phazon.
No, no, no... if we evolve with phazon from a normal metroid phase, we should instead be a fission metroid, no? Especially due to the fact that we evolved on Tallon IV, and there are no phazon metroids naturally occurring on Tallon IV. Think for a second about Metroid Fusion. The reason that Sector I, a perfect replica of SR388, was created was so that metroids would have a natural evolution cycle. The same could be seen in Metroid: Other M, on the bottle ship. In both games, and in Metroid II, Return of Samus, metroids evolved along their natural line. However, in any other game, metroids seem to evolve along a totally different path based on their climate. On Tallon IV, metoids naturally evolved to a hunter metroid phase, or evolved to fission metroids due to phazon radiation. On Aether, Tallon metroids turned red, or got possessed by ing and turned black. On the pirate homeworld, under a barrage of phazon radiation, Tallon metroids turned into phazon metroids, and hunter metroids turned into metroid hatchers. The only way metroids turned into metroid primes was through being nurtured by a leviathan. We don't know what stage a metroid was when it was being nurtured by the leviathan, but it's safe to say that it was a fission metroid based on the presence of those enemies in the impact crater.
Thus, shouldn't we be a fission metroid? And, if our next step is in fact to become a prime, should we not make it our goal to enter the impact crater, slay whichever metroid is being nurtured in the leviathan, and become the prime?