[Chapter 447 spoiler] Why do these people cooperate?

With the current chapter it has become rather clear that Baal and Narnia still work together.

Baal sacrificed Shiida who has become a liability and let Narnia use her to bait Iruma.

Henri has been informed about Shiida and proactively works with Narnia on the case since they pull up together to Babyls from what I can tell.

So why the hell would Henri, after all he did and went through, go ahead and lead Narnia right to his true target, Iruma, given Narnia's clear aggression? Henri would've been able to handle Shiida just as well.

What I figure might be happening is this:

I believe that Henri backs the Human Deportation Act after revisiting his history with Merize when telling the entire story to Ameri. Narnia without a doubt threatened Iruma's life during the Deviculum and wouldn't have minded a slip of hand from Azami.

However, his goal is to clear the Netherworld of "foreign objects" for now (magical beasts and what he considers lesser demons come later then, facism often works step by step where the most vulnerable groups get targeted first and then more boundaries are pushed afterwards).

Whether that is by killing them or getting them to disappear in other ways is irrelevant to his goal.

So let's assume the current goal is "No humans in the Netherworld". Henri acts as his foe on this issue in particular - the other people Narnia wants to dispose of have only been addressed in passing, like when he was first introduced and his outstanding ruthlessness was pointed out, and now again with Shiida, a criminal. Henri either does not have any gripe with what happens to random demons and magical beasts or (most likely) is not aware of that part.

So if Narnia's idea is sold as "Remove humans" and not "Kill humans" it's not only something that is safer and more merciful than Knightwalker's legacy on using living beings for inhumane experiments, but also something Henri might be on board with in the end to protect both Ameri (from heartbreak and being outed herself) and Iruma (from becoming a guinea pig or simply randomly killed because he's more squishy than demons or randomly falling ill like Merize - especially if he has no knowledge about Iruma's former life).

Depending on if Henri is fine with this, the question is how they'll handle the deportation. Kushinachi does not seem to be around and we saw one of her heirs have weak mana (her granddaughter went to the same correctional institution as Kirio), so there might be no direct replacement (this is a stretch since we don't know if she has other offspring with strong enough abilities).

The only other person we can assume (since it's not outright confirmed) to have similar abilities would be Wett, which Baal won't officially lend to the Border Patrol.

So how do they pull this off anyways?

Well, Henri could be baiting Narnia, even now. Sullivan is currently a big question mark and he has history with Henri. Their moral compass also seems to align. So Henri is in the unique position to genuinely cooperate with Narnia for his own agenda while being reassured that Iruma will be fine if he has some kind of B plot going on with Sullivan preparing something either in the transit to the human world or the human world itself (which is more likely if he is sent back alone like Merize was).