Julien killing Koral is such a good character moment - that whole scene. He's made it a life goal to kill as many Tachonis as possible, but because Occtis asked him to, he was willing to talk to Koral first and maybe spare his life. It's only when he realizes Koral was an unrepentant actor in the massacre of his family and home that he decides to kill him.
The Julien Davinos of two weeks ago was so angry at his losses that he wouldn't have hesitated, but he's calmed down just enough, bonded just enough with Occtis, that he waited to be sure that Koral deserved to die before killing him. I said ages ago that everything Julien does has to be viewed through the lens of someone furious in grief, and that he would probably change as time went on, and I think we're see the start of that.
