Several things happened within a relatively short window that added dismay and surprise to Claire's growing freak-out. Dean's eyes kept opening and shutting. Ruby had offered the demon knife to use. Dean was hitting on her and talking about sex (all right, no surprise there). Dean hadn't reacted to Ruby and the knife with a desire to stabstabkill, and instead had thanked her.
And again, for anyone who had missed the point, Ruby had offered the demon knife.
For a frozen moment, Claire stared up at Ruby, waiting for some kind of punchline, waiting for the demon girl to realize what she'd done, to realize she was passing a fatal weapon into the hands of someone who might just kill her while this harried... and then Dean spoke and tried to move, effectively breaking Claire's frozen moment.
"Mine, now hold still," she said to Dean, sounding overwrought rather than suddenly possessive of the demon knife, then turned to Ruby.
"Thanks." And with no more ceremony than that, with no more thought as to the weight of what this knife could mean in her hand except as a method to save Dean, Claire took the knife from Ruby, held her forearm over the worst of the gunshot wounds, and drew the knife blade hard across her forearm, through skin and deep into veins. As expected for so serious a wound, there was a rush of blood, as always looking so normal and giving away no hint as to what a quirk of her abilities provided for others.
Yes, she could feel pain, but she didn't feel any of it this time. Her focus, everything she had, was on that wound and her blood flowing into it.
And then the goddamned gash started to heal. Fuck. Blessing and curse, rolled into one right now.
What bled more than the radial artery? What had the medical books of Peter's said? Brachial, the vein in the forearm, the vein closer to the heart. The closer to the heart the faster the bleed. The jugular bled faster still, but maybe cutting her throat wasn't the best option yet.
Swearing, she adjusted her arm over Dean, raised the knife and sliced into her upper arm, this time holding the blade in the wound, twisting to keep the vein open. The pain was felt distantly, but was ignored like her other unattended wounds with obstructions still in them.