It's me again, and i have another question. I just finished Jaethal's last quest (Reveal my Destiny) and because i convinced her to do the good thing and spare her daughter, she rejected Urgathoa's gift and got disintegrated by the Goddess as a result. Which means i lost a party member and, more importantly, my Spy Master (the Minister) -_-
Now, it seems like i can somehow fix the advisor problem by appointing Kester as the new Warden and re-assign Ekundayo to the position of Minister (i had him do the Warden job up until now), but before i do that, i want to know if i messed up something unknowingly or if this course of events is the normal, natural consequence of my choices throughout the game.

In other words, do i have to complete Jaethal's quest the evil way in order not to lose her, or is there some trick to somehow prevent her from being removed from the game even if i do things the good way? I know Jaethal is an evil character who's done terrible things in the past (and would have done more if only i had let her), and i'm not particularly fond of evil characters in games (Nok Nok is funny though) since i like to play the hero, but still losing a party member like that so far into the game kinda leaves a bad taste in my mouth since i was expecting her to go the Viconia route (having an alignment shift and becoming slightly less evil as a result) rather than go boom and vanish. On the other hand, letting her sacrifice her own daugher right at the end afer i had her spare a complete stranger and reject the old priestess offer previously doesn't make sense from a role-playing point of view, considering that my main character started as lawful good and now is neutral good (i agreed with Tristan a bit too much XD) and so he wouldn't agree with such a decision.

So, is there a way to save both the daughter and the mother, or i must sacrifice one of the two? If it's the former, i would like to know how. If it's the latter, then i'm probably going to keep things as they are and reluctantly say farewell to Jaethal since i really don't like doing evil stuff. I just want to be sure before i progress with the game and move on.

Without spoilers: to achieve optimal "good/happy" ending for Jaethal you have to get her to reject Urgathoa with Tristan in your active party. And before that you have to finish Tristan's personal quest with Jaethal in your active party (only his last quest matters).
Otherwise you'll get very disappointed in the last chapter.

Found this out the hard way, like many other things recently, on my first play through of the game. I almost feel compelled to replay it with the knowledge I gained from the first play through, despite the LARGE number of hours that took!

I had Tristan in my party when i did Jaethal's quest, and i had previously completed his personal quest (assuming the part when i forgive him and let him join the party again is the end of his quest. I'm not sure since i'm still on my first playthrough and i've not finished the game yet). I don't remember if Jaethal was in my active party at that moment though, since i don't usually pick her. Is that the reason why she exploded? If it is, how was i supposed to know that?

She always explodes when she rejects her goddess - the important part is what happens possibly dozens of gameplay hours later. Really can't write anything more without spoilers. You'll see when you get there, and you'll immediately know if it's gonna be a "good" ending for her.

I see.