[X] Ask her what she's talking about.
-[X] Encourage Riona to talk. Ask simple, prodding questions as necessary. Don't push too much.
-[X] Try to learn:
--[X] Riona's expectations, past and present.
--[X] Riona's reasons for her actions, and for telling us all this.
[X] Afterwards:
[X] Clarify: If she lets us help, we'll help.
-[X] We'll ask:
--[X] She stops killing while we work together.
--[X] After her problem is solved, she stops killing and releases the unwillingly taken Souls.
-[X] Ask her to consider letting us help. For real, none of this 'only way to help would be giving our soul' BS.
--[X] Ask her to take a few minutes to actually think about it.
[X] Meanwhile... ask if she can keep a secret. If so:
-[X] Bring up de-Witching.
[X] She doesn't get it, does she?
-[X] You don't need preconditions. You'll help her, because you'll make the world a slightly better place by doing so. And because you'll be able to get her to agree to things afterwards.
--[X] When people have something they'd watch the world burn before endangering, you don't open negotiations by demanding they endanger it. You open negotiations by ensuring its safety.
[X] Before Rionna decides her end, she needs to explore the truth of what Sabrina is saying, and she can.
[X] Sabrina wants to save even witches. We don't send them to Kyuubey already. The witches don't pay us anything.
[X] Rionna must have used countless powers until now. Another Shade can't help her.
-[X] What she needs is someone to cast the magic along with her, isn't it?
[X] Anri is our example of morality, tell the story
[X] The only way to move forward when one has done everything they could do is to do things differently than ever before. Sabrina is the person who acts in the way that won't hurt Rionna. Who else has helped with her problem?
[x] I do want you to stop. But if I refused to help any magical girl who was forced to do something awful... there wouldn't be very many girls that I could help left.
-[x] If I manage to help you, and if what you've done is no longer necessary afterwards... won't you want to stop, yourself?
-[x] What is it that you're working towards, that you're gathering so many grief controllers for? Reversing the witch transformation? Trying to reinstate a wraith? Tell me.
[x] I do want you to stop. But if I refused to help any magical girl who was forced to do something awful... there wouldn't be very many girls that I could help left.
-[x] If I manage to help you, and if what you've done is no longer necessary afterwards... won't you want to stop, yourself?
-[x] What is it that you're working towards, that you're gathering so many grief controllers for? Reversing the witch transformation? Trying to give a Shade a body again?
[X] It isn't a lie. You want Riona to stop but you can settle for postconditions.
[X] But what is Riona's problem she keeps in Edinburgh anyway? Somthing to cleanse from grief? You're working on cleansing enchantments and can refresh Grief Seeds indefinitely. Dewitching? You've been working on that and gotten some results
-[x] If Riona shows interest or challenge us to our claim, bring the Clear Seed again and let her examine it. Explain technical differences between Grief Seeds and Clear Seeds (clear seeds feel calmer, etc). After that, insist on the question about what's in Edinburgh.