im rereading gtn and wondering why cytherea wanted gideon and harrow to complete the avulsion task with her? Was she hoping theyd die unsuspiciously in the task? Or did she genuinely want to learn something from it?
I think a huge part of why Cytherea's motivations are so confusing is that despite apparently contemplating something like her actions at Canaan House for the last three centuries, she rather seems to have gone into it without a plan.
She loves John. And she wants him to die. She loved Loveday and she's had to live with the failure of her death to achieve its aim for 10,000 years.
Her statements about people and her intentions towards them are so often contradictory. She calls the Fourth "the children" and observes them benevolently, then later takes a perverse joy in killing them. She's so wildly out of touch with the contemporary culture of the empire that she's unaware of Abigail Pent's career. She kills Dulcinea in cold blood and then sentimentally talks about keeping her corpse in her room.
When Gideon is dying in her arms in the avulsion chamber, she tells her "none of this is worth it, at all...It's cruel. it's so cruel...I'm sorry. We take so much." But later, she announces that "I have come back home to kill the Emperor and burn his Houses. And Gideon the Ninth...This begins with you." And later still, she says "You're not going to die here, Gideon. And if you ask me to let you live you might not have to die at all."
We learn she asked the Sixth, and they refused. So she asked the Ninth. Was she trying to get a measure of pairs? To kill people? Did she have entirely different motivations in asking the Sixth and the Ninth? Did her motivations change part way through? The problem is, from what we know, any of these could be possible!
If we believe Mercy, then Cytherea would have immediately recognised the significance of Gideon's eyes. I do wonder if the avulsion trial was a situation where she got something useful however things fell: if the Sixth had done it, she would either have gotten a sense of what the current generation of necros were capable of, or she would have bumped off another few scions. But they say no, so then she asks the Ninth. And if they had died, again, that's fewer scions and a mounting sense of panic and confusion to lure John closer to the system. And if they didn't die...well, she'd know she was right about those eyes...