When Rin wakes up it is damp and cold, she can feel grass against the skin on the back of her neck. She jerks herself up, noting the surprising lack of sudden pain, and opens her eyes to search for the Kiri nin that had just ambushed them. She can't see a thing, even when she blinks several times. As the memory of kakashi's chidori comes back to her, that was why she was on the ground, she had decided to-
Rin reaches for the gorey entrance wound on her chest that adrenaline and iryo-ninjustu reflex must have numbed. There is nothing there but the untorn cloth of her shirt. The fatal wound on her rib cage is gone and she suddenly realizes the seal's awful compulsion is too. She must have succeeded then, Kohana would be safe. She flops back into the long grass and breathes out, she never imaged the pure land would be so cold and dark but at least she is no longer being forced towards her home knowing she carried it's destruction inside her like a ticking seal tag.
She opens her eyes and her chakra senses to feel around her for other people, she cant feel a single one. As she lies in the grass staring into the darkness and stretching her focus into the emptiness around her, her eyes adjust and she begins to pick out lighter and darker patches above her, trees against sky she realizes. It must be particularly densely clouded dark night, there are no stars above her and the trees almost look black.
As she squints at the dark sky she realizes that the damp and cold she felt when she woke up are part of a large cold charka presence that she didn't notice because it stretches all around her and is very faint in any one spot, just like the groves of hashirama trees that she used to practice her sensing on because they were so faint. She sits up again, suddenly unnerved, the presence is very similar to hashirama trees only it feels like clinging moisture surrounding her on all sides not soothing green she can trace back to a single tree.
For a second she thinks she might be inside a huge suiton technique and she jumps up and turns around. As she does the trees in front of her are eclipsed by a blinding bright disc that slides into being as if it were and eye being opened. the light from the disc is blinding to her unadjusted eyes and it takes her a second to realize that it really is an eye, a single eye set in huge armoured face. Was this thing behind her the whole time?! Rin scrambles back agew steps, panic and shock taking over. The huge head draws back.
"peace little shinobi" the spikes on the creature's jaw shift as it speaks "your heart and left lung were punctured, you must not waste energy"
"The Sanbi..." Rin breaths as she finally recognizes the chakra and the red ringed golden eye. The old woman that had been dragged into the ritual room covered in chain and sealing tags had eyes exactly like those. Rin had been tied down on the floor already but she had seen the other woman be chained down across from her. This creature's chakra was the same as the overpowering nature chakra she had felt in that room
"I am Isobu" the Sanbi speaks again "you are on the brink of death, come closer and I will lend you my chakra"
Rin takes another step back "You can't! I have to die to protect my village. I can't fight the seals compulsion"
"If you die I will be dragged along with you and i am not so bitter as some as my brothers and sisters that I wish pain on my jinchuriki just for the part they unwillingly play in my imprisonment. There must be way for us to trick the seal, surely you sensed your friend is almost out of chakra and you two are surrounded by enemy nin, why would they be chasing you if the seal was unbeatable"
"Kakashi-" Rin shivers, remembering watching kakashi fall to the ground next to her
"Yes you must save your friend" Isobu raises his head and she can see the red skin of their neck
Rin considers for a minute, hands twisting her apron. Isobu obviously has a stake in her continued survival but they're right about would it do to him to wake up and realize what she had used him to do? What if the kirinin got to him and he never woke up at all? She can sense the location of all the seals on her and she can tell it's the one on her heart that is forcing her toward Kohana. It must have been at least partially damaged by Kakashi's first and with her medical knowledge and what Kushina-nee has taught her about fuinjutsu maybe she can open up her chest and overwrite the seal if she can use the bijuu chakra to heal herself as she does.
Finally Rin steps forward "I want to save Kakashi, But I won't just hand over control to you! My Nee-san has a demon too and I know how manipulative they can be"
"I told you i'm not like my brothers and sisters, if you don't accept my chakra you will die and and your friend will most likely follow you" Isobu's Huge eye blinks, Rin thinks they look frustrated.
"I still need some kind of guarantee you aren't lying to me" rin shoots back
"Haven't you noticed there are no bars between us, Your seal isn't like the cages i've been in before, if I wanted I could devour your consciousness right now and take control, but I'd still be trapped in your mortal shell and the seals on it would still suppress my will' Isobu's rumbling voice gets louder, they're definitely frustrated now
That's enough to convince Rin, this seal is clearly a cage for both of them "okay i'll take your chakra" Rin shuffles through the grass toward isobu's huge jaw. Isobu lowers their head again until their jaw rests on the ground at rins feet, she's now eye level with the tailed beast
"Put your hand on me" Isobu rumbles and rin complies
As she places her hand between Isobu's eyes she feels a concentrated rush of cold nature chakra flood her chakra coils
"When you leave our seal space you must stay still or my chakra will turn you coral" Isobu shell rumbles under hand as they speak
"What?! That kind of thing doesn't happen to Kushina-nee when she channels her Bijuu's chakra!"
"I can tell you have a water affinaties, my chakra is also water so you body won't be able to balance out my chakra with its own, unless you've mastered controlling nature chakra?"
Rin shakes her head mutely.
"Just stay still then, you probably shouldn't be moving with wounds like your's anyway"
As Isobu talks Rin can feel them pushing her out off the seal space. She takes one last breath of damp air and then the pain returns and she can't breathe at all.