I really feel like the Union's role in this article needs expansion. Perhaps a series of letters between Union members detailing the attack and failed rescue attempt from their perspective? If so, perhaps you could have it so that the Union was successfully able to save some of the prisoners taken by Eden's Forest. Perhaps you could also make it so the Authority got involved soon after the initial kidnapping, as the Union would have undoubtedly tried to contact the police about the incident. The Authority would probably have an MST posing as cops take up the case due to the anomalous nature of both kidnappers and victims. Perhaps the Authority could have even been working with the Union to deal with Eden's Forest, with the Union giving them information about the GOI.
There are also some consistency and tonal issues with the interview with RPC-550's father. For one thing, the authority should have been able to figure out his relation by looking up medical records, and both the Authority and father should have been aware of Eden's Forest kidnapping her by the time of the interview. Information flows fast through the Union. And amnestics would be pointless on someone who's already aware of the anomalous.
Honestly, I think it would have been more interesting narratively if both the Authority and the Union reached Eden's Forest's hideout at the time the ritual took place, resulting in a dramatic 4 way between Eden's Forest, the Authority, the Union, and RPC-550, perhaps even having it so that the father was there as well, and they busted into the room just a second too late to stop the ritual from being completed, or perhaps even disrupting it at a crucial point between the loss of her consciousness and the replacement with the consciousness of whatever they were trying to summon, resulting in RPC-550 becoming the mindless monster it is today.
Speaking of, if RPC-550 is meant to be a mindless monster, she shouldn't have the sapient hazard; only the sentient one. If she is in fact meant to be sapient, have her show some signs of humanity. Maybe the last minute rescue made some noise that gave her just enough hope to save a sliver of her consciousness. Maybe there's still a scared little girl within that's struggling to get out, resulting in her constantly weeping in anguish. Maybe she has enough willpower to reason and communicate, but is constantly fighting against the force that wants her to kill whatever non-plant lifeform she sees, resulting in a terrifying paradox where she simultaneously needs the comfort of another human being and needing to stay away from them to avoid killing them.
That would make her significantly more terrifying than just being a "thing that kills you."