while i'm fine with wit and jasnah's relationship in row i'm kinda worried, knowing hoid's shadyness and his role in the cosmere as a whole, that he doesn't end up betraying her or using her or he turns out to be the actual big bad of the cosmere or something
HELLO FRIEND. I realise u sent this message Many Moons Ago, but what u have to understand is my memory is non-functinal. It's as broken as my impulse control. So u know. This is why this answer is Very Late. BUT. It exists. So. Yay for that I guess??
ANYWAY.
I don't agree that Wit (I'm going to go with Wit since that's the name he's using on Roshar/what Jasnah knows him as, and for the sake of ease on this post, I'm just using that one name) will be the eventual BBEG of the Cosmere. I believe that, fundamentally, his intentions and motivations are generally good.
Regardless of that, I understand the Concern there for Jasnah with him betraying her/using her/sacrificing her for his greater good etc etc. She's suffered enough fucking betrayals in this series already, man alive.
I hope/believe that Wit is someone she can trust/lean on for support and confide in as a mutual and a partner, as she's been doing in RoW, and I really hope he won't stab her in the back/betray her in the standard, trust-eroding way she's used to.
HOWEVER. I do recognise your worries and I've considered them as well and what it boils down to for me is that: he's been honest with her about who and what he is.
Jasnah is not going into this blind. She's not going into this thinking he's just a strange little man who likes to insult people and make good puns in her direction. She knows that he's ancient. She knows that he's a worldhopper. She knows that he's trying to protect the Cosmere as a whole.
He seems to have been more open and forthright with Jasnah about his goals than he has with pretty much anyone else as we've seen him in his various small roles across the Cosmere.
She doesn't know the specifics of what he does. For example, he hasn't yet (that we know of) confided in her about where exactly he goes and what exactly he does when he vanishes from Roshar. But I feel like she knows enough.
“Perfect for you. If this is agreed to, you win no matter what. Odium remains contained in the Rosharan system either way.”
While they're discussing the contract with Odium, which Wit had a not small hand in writing, Jasnah makes this comment to Wit. She knows who he is, and she knows what he's willing to sacrifice, and what his ultimate goals are.
He's been honest enough with her to explain the wider Cosmere to her, his role in it, his fears regarding Odium, and his desire to trap the Shard on Roshar, at the very least, to stop it causing any more harm than it already has.
The short version of this answer is that I think, if a time should come when Wit has to choose between Jasnah and the Cosmere, he'll choose the Cosmere. But. Jasnah knows this. Jasnah knows that he'll choose the Cosmere over her. And, what's more, I think that Jasnah would agree with that. And that she would choose the Cosmere over him, too.
So, if Wit betrays her, it wouldn't be a standard betrayal of the kind she's used to. It would be one he has her blessing in, almost. Which is a bit sad, for both of them, because I think they both accept/have this condition in place. But it lets them function openly and honestly. And it lets them trust each other, in a weird way, knowing that's always an option, and that they'll do what they both believe is the right thing if they're forced to choose.
I believe that they've communicated with one another about this. He's told her what he wants and what his goals are - at least in terms of Roshar and Odium and things that concern her. And she's shared with him the same. And I think they understand each other enough, and are actually similar enough, that even if it comes down to it and one of them has to make that choice - they'll both understand and agree with it?
It's actually kind of a fascinating dynamic. There are a lot of complex layers at play with this relationship. But they're two intensely complex characters, with complex motivations, and drives. And I think they've been as honest with each other as they can, as they try to balance building a deep, meaningful connection and relationship with another person; while also trying to save their planet/universe at the same time.
It's never going to be perfect, but they're doing the best they can with it to make this as healthy, committed, and positive relationship as they can. Not just for each other, but for what's most important to each other as well.
So I guess the tl;dr is: yes, Wit may be a shady fuck. But Jasnah is also, technically, a shady fuck. They're two shady fucks together. Who know they're with another shady fuck. And they've discussed exactly what they're trying to achieve, and the lengths they're willing to go to to get it. So if one of them becomes the alpha shady fuck, the other one will be aware of that/supporting them in all their shady fuckery.
Wow. I'm so immensely eloquent tonight. ur welcome.