this is so completely wrong in every way . i am so going to sound like a total jerk (i mean more so then i inevitably end up sounding) but if you don;t understand the tradition don't try and explain it. also what the heck does your first sentence mean? it;s entirely contradictory to it's self.
I understand the tradition as Thanaton himself explains it. Zash was killed, therefore everything Zash built was to be destroyed. It didn't matter that the Inquisitor killed her. What matters is that Zash was killed. That's what I meant. Thanaton specifically explains this during the first part of chapter 2. He never says anything about killing the Inquisitor for killing Zash. Heck, he doesn't even know
at first. But since Zash was killed, tradition demands those who served her die as well. He makes that perfectly clear.