We've got to work with what we have: An angry person that doesn't want to listen to us.
That means we can't inform her of anything whatsoever at this current time; we have, in fact, told her she's dying, but she's not in a state of mind to listen to anything we have to say.
My first vote tries to say things that will appeal to her current mindset: She's angry, she wants to be angry, so saying things that'd make her angrier would have an effect.
How about this, instead:
[] Squeeze Mami's shoulder in thanks.
[] To Ono: "Tell me
more."
-[] Let her yell at you, try to get her to throw all her frustration at you, while you can keep an eye on her Soul Gem.
-[] Prod her along; mention how rude you've been to her, from your first meeting when you all pulled her into this gray world and bound her, then forced her to make a desicion without much of a choice; remind her how you found yourself more important things to do rather than attend your meeting, so you simple postponed it on a five-minutes notice; tell her how you really want everybody to do things your way, simply because you think it's best, and expect the same out of her.
Somewhat more understated, since I see some people don't want to be blunt about this.
This would be the less aggresive approach to leading Ono into a mindset where she will listen to us. She's angry, so what we can do is use that anger, feed it a little, let it burn through Ono's energy and will, until she's too
tired to be angry. Until she can't hold on to it anymore.
Then she'll consider other ideas, but not before.
She isn't ranting right now. She's glaring. And no. At this point I don't think weathering it out is worthwhile.
I don't think we can do anything but weathering it out.