Let me talk about my understanding. It is an unknown life form higher than aliens (the consciousness of the universe is said in the play?) It needs the energy of a planet, and over a long period of time, it has "recruited" the civilization of the planet, and at the same time evolved new human beings. They don't seem to be evil, after all, they allow life on earth to continue - because they retain the seeds of human beings (those new humans), as well as other life on earth (pack life to the mother planet), and finally absorb the planet energy that ended the planet.
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