So the witches that we see here are called Ladies of the Midnight. So it makes sense that they would fear Diana, who can be seen as their prophet. Still, Elstri going after Diana isn’t what the king requested, so there is still the issue of her making things harder despite wanting to prevent the prophecy. Eliminating Julian would bring her closer to fulfilling the prophecy rather than avoiding it, especially since the witches made contact with Diana.
Though it is clear the threat these witches present as they fight Atlus. Still, it seems that Atlus isn’t judged for his own kills. As it is viewed separately from Arkos most likely. In fact, his heart still beating comment is intriguing. I wonder if that is also because he is a resurrected form of Arkos?