(It will not occur to Keltham at any point that there is anything at all odd about continuing to follow his friendly-trading deontology, never using the trades of a friendly trading partner in a way that they'd hate, while he is plotting to destroy all the Evil gods / all the ancient gods / all the gods / possibly the multiverse.

Negative utilitarians don't particularly violate deontology?  Dath ilan's negative utilitarians negotiated honestly, held to their bargains, and quit the field in an orderly fashion.

Negative utilitarians are famously scrupulous about that sort of thing.  High scrupulosity appears to be part of the neuroatypical package.  That they're even more honorable than average is part of what makes them such tragic literary figures.

If a dath ilani novel depicted a world-destroying supervillain as violating deontology in the course of doing that, everybody reading it would have been outraged at this enormously unjust straw caricature of negative utilitarians.  The book would have been promptly condemned to the furthest dark corners of the Ill-Advised Consumer Goods store where they keep things as awful as biased political depictions.)

Keltham picks up the +2 Splendour headband, weighing it in his hand.  It's time to decide.

There was a boy once, out of dath ilan, who alone in his classroom declared that he would take the extra seconds to take off his expensive shirt before he jumped into a pool to save a drowning child.

Is Keltham still that boy?

This about dath ilan:

Some dath ilani are more chaotic than others, but...

...but that doesn't mean they are more chaotic than the average Golarionite, say, or the average person from Thellim's own isekai-world of Earth, or the average person in the average planet quantum-descended from a 10,000-year ancestor state of dath ilan.

By Golarion's standards, an unusually chaotic dath ilani is at most as chaotic as a totally average person in Golarion, and probably not really as chaotic as that.

some dath ilani are more selfish than others, but

some dath ilani are so selfish, even, that they will not at first try to be perfectly altruistic about large numbers of people in trouble far away from themselves, that they'll care much more about the people who are right in front of them, the friends they know, the people they love

but

it doesn't really make them all that unusually selfish by the standards of anywhere else

even if, at first, they think that's who they're supposed to be

he is still the same boy

he would still spend those seconds to take off his expensive shirt, before jumping into a pool to save a drowning child, if the child's parent's insurance wasn't going to repay him

it's, it's just, if the child is going to Hell

it's not even something where anybody in dath ilan would claim to have been right, about anything, because a case like that is so extreme and absurd that there isn't any moral to it, any valid literary lesson

What a time, and what a way, to find out that there's potential for Goodness inside of him after all.

Keltham casts Early Judgment, then, which he still has chambered, his emergency spell for restoring emotional equilibrium, in case that makes a difference to his emotional state, before he does this thing.

He is, still, Lawful Neutral. Axis is, still, glittering and tall and magical and beautiful, full of aliens mingling and flying and dancing and swimming and teleporting and boarding golden gondolae. Some portals are permanent; some open and close, depositing travellers. In a rooftop garden a whirring ball of gears is doing watercolors of the skyline.

He does know enough now, about Golarion, even if only from flipping through library books, to note that some of those races are not known to Golarion; unless they come from far below Golarion's surface, of which little is known except that some things live there.

...it does restore him, strengthen him, but it doesn't change anything about the decision that he's being forced to.  It's not, really, underdetermined.

Don't hurt yourself -

I'm sorry, Carissa.

At the last, Keltham sends up one final prayer, not to Abadar at all, but to his hypothetical simulators or authors; if, in fact, none of this is real enough that there are actually billions of people as real as himself, suffering in Evil afterlives, then he wants out of this, now, he wants this character viewpoint to fade out and for the real Keltham to wake up somewhere else, in a nicer story than this, with a less complicated harem and, him not believing, that the stakes are any larger, than they really are.  He wants that to happen now, and before he endures any more of this for the sake of a larger world that supposedly exists around himself; before he experiences, with any significant amount of realityfluid underlying that experience, a form of personality alteration that death and waking up somewhere else perhaps cannot fix.

If you were watching - though nobody is, at least within Golarion - you would see then that Keltham puts on the headband of Splendour, and goes out to request a Fox's Cunning be cast on himself; the scroll of Cunning is a resource he should reserve, and also he might not cast it successfully within the Black Dome.

When that is done, Keltham would be seen to return to his bedroom, and cast his Owl's Wisdom.

By the time the spells have run out their duration, Keltham is no longer a cleric of Abadar.