Cyner
Too little too late
Metroids are... considered the ultimate life form, they are just different than anything else.
They consume life force because they were created as a predator to the most vicious parasite the galaxy has known, which apparently unless you're a Metroid, takes planet busting force to kill one. When exposed to radiation they absorb it and gain new abilities, when exposed to beta rays they speed up their own replication and growth, when Phazon is introduced they easily add it to their genetic makeup. Just introducing a Metroid DNA based Vaccine into Samus gave her the ability to absorb X on contact. In Metroid Prime if you read the space pirate logs it points out that they tried to control Prime and it would destroy and absorb their weapon systems and add it to it's own arsenal. Besides, if they could be mind controlled wouldn't the GF have already attempted to do it with their telepaths?