Firstly, he owes us, if we ask him to keep quiet about Odr stuff he likely will. It's not the sort of secret he'd feel obligated to share, for reasons I'll get into below.
He owes us, true.
Not the kind of secret he'd feel obligated to share?
I doubt that. I highly doubt it.
He may not feel it important or appropriate to share, but I bet other Christian cultivators will ask him about his stay and find it interesting and try to bore for things he isn't telling.
Not certain doom, but a real risk.
If i can't convince you that it is a bad idea, could you include asking him to swear "to keep secret what we tell him and other secrets of the Norse he may come to hear"?
Secondly, and perhaps most importantly, it's not actually that useful to Christians anyway given its rarity among the Norse...like, what is the actionable military information there? That most of the Norse are weirdly fragile by the standards of Knights (and basically no other standards) due to uninfused stats? They knew that. That they have an Enemy who is attempting to restrict their Cultivation? They can't really utilize that without allying with a literal foreign devil...I can't imagine that not being more Sin than you can shake a stick at and thus not really viable...assuming the Enemy would even go for that (I suspect he would not). That the Norse need to own land to cultivate? I'm pretty sure feudalism was already the plan if they actively conquered the populace, and it doesn't stop Orthstirr use anyway. Like, knowing what we know about how Odr cultivation works doesn't actually reveal a whole lot of weaknesses that are militarily relevant, so I'm unclear why one Christian knowing that info is an issue.
It can help them figure out other clues they find.
It allows them to customize their messaging when trying to convert.
(One option: make the Gate out to be a secret proving the power of Christ, something only true believes in Christ may open. Then show the convertee how to reach the Gate. If someone tries to open the Gate and dies use that as proof of the power of Christ as they weren't true believers yet. (True believers being deep into Feudal Christian cultivation))
It gives them a better model to understand the strength and weaknesses of Norse cultivators.
They need not work with the enemy to understand that it limits Norse cultivators growth, they could make traps based on it (like hints to true cultivation that are misleading and make the attempts much deadlier).
The land ownership part?
Has implications on the mobility of Norse cultivators for prolonged conflict (needs to return home to cultivate).
Has implications for backhanded deals (if you have to give land to Norse, try to make sure it isn't valid for true cultivation).
I'm unclear why one Christian knowing that info is an issue.
Both for the uses and the danger of spreading:
Gabriel will be exposed to courtly intrigue again when he returns.
His will and ability to keep it secret will be challenged by the vipersnest that is courtly intrigue.
If he fails, how to use it to harm us will be worked on by the same vipersnest.
Thirdly, all they need to learn this is to convert a single Odr cultivator to Christianity. You think that's never gonna happen? I'm pretty much positive it will, and hell, maybe already has. Like, Odr cultivation is a secret but it's not a secret you don't want to tell your friends, so some Christian is gonna learn this at some point, there's value in putting it off when it becomes widespread, but see the first point above.
They'd need an Odr cultivator.
Something rare.
One Faction knowing that secret has the goal of freeing the Norse (Blackhand, Ironjaw who knows how many more, potentially all Blackhand descendants named Hallr, (we may be the odd one out by not knowing If/how many allies we have in this fight ) ), a goal very at odds with conversion.
A different potential faction being those who embrace the curse of Steel and want to keep Odr a secret, because being stronger than others gives you power over them. Highly unlikely to convert and give up their privileged positions. (If they embrace Steel for its unchangingness, then conversion would be a huge change)
Fourthly, Gabriel is from a full cultivation tradition with its secrets not all jealously guarded by a petty dick. I'll bet we can get him to reciprocate with some of the real secrets of Feudal cultivation, which may well be very worthwhile in figuring out the Norse version. An information swap of what we know for what he knows is very much in our favor.
We could learn things about his cultivation, true.
We might want to try to steer the discussion to him telling us stuff if that is our goal.
Also, lesser caveat: He may remember that he isn't supposed to share Christian cultivation secrets. (With Jerasmus I'd call it a problem, but with Gabriel its probably just gonna dampen a bit how much we get)
Using Christian cultivation info to figure out Norse cultivation... might work, with the culture is foundation of cultivation I'm much more interested in exploding Halla to more facets of Norse culture and seing how those facets could fit into cultivation, but thats just a personal preference.
Fifthly, Gabriel presents a possible way around the Enemy's disclosure restrictions. Does him telling the Enemy about Odr Cultibvation provoke a lethal attack? We do not know, but I'd very much like to. That would be an interesting thing to experiment with...
Possible, interesting to learn.
Not very interesting option to take, imho. But would be good to know.
Hopefully he doesn't decide that our Enemy must be his God.
Nah, he knows we wouldn't expect him to help us in that case.
If he had the idea (not saying he would), the "but would she ask us for help against God?!" question could be answered easily with "How would she know that herb 'enemy' is Good?".
