Isolated incident - it was a shinki who was using loyalty to his god as an excuse to murder anyone he perceived as a threat. Which was just anyone unlucky enough to be an easy target. [Shun definitely sounds bitter about that, in a way that can't really be concealed. At least one of the deaths in that string had led to strong personal repercussions for him and his temple, and there's definitely more than that who were killed that he would have much preferred not to lose.]

Not that getting information out of him went that well. He felt his god disappear halfway through the interrogation, and I had to kill him before he turned into an ayakashi.

[Unfortunate, maybe, but Shun sure doesn't sound disappointed about having been the one to kill him.]