That shaman-looking regalia did the “Evil Smirk at the End of the Episode”, so there was a good bet he’d turn out to be a less than swell guy, and this episode confirms that with all the subtlety of a Hiyori Iki Suplex.
Yukine comes clean about having made a friend outside the Circle of Trust, but everyone’s happy about it, and Yato, while a little weary that Suzuha is a Bishamon regalia, merely urges caution going forward.
Suzuha already has Yukine in his thrall with his friendly demeanor and approachability, but seals the deal by telling a very sad tale about a girl who used to notice his flowers every Summer, but could never remember him, and forgot about him altogether thirty years ago, when they promised to meet at an old cherry tree he’s now desperately trying to rehabilitate.
Suzuha’s longing turns to obsession and despair one night, after the shaman-looking guy (named Kugaha) seems to twist the knife, telling him even his master has forgotten him and that he has nothing. A pack of phantom wolves then kill Suzuha right there, and Bishamon, who may well have forgotten Suzuha what with the legions of other regalia she has to keep track of, only wakes up when she feels the loss.
Unaware that Suzuha is gone, Yukine arrives at the time they agreed on for a picnic, along with his friend Hiyori. Yuki makes no bones about his concern about Hiyori forgetting about him when she grows older and moves on with her life, both to Yato and to Hiyori herself, but she tells him not to worry: she’s not going anywhere. At least, not until she’s satisfied Yuki has gotten a good academic education. When/if Yato fixes her tail problem, even she can’t say what will happen, but she doesn’t want Yukine to worry.
The pain from Yukine’s worrying, after all, is also felt by his master Yato. So it really puts into perspective how much pain Bishamon endures every day from the collective pain of her myriad regalia. And she only knows it’s Suzuha who is gone when she spots a dead plant in the hall; all the low-level regalia put on happy faces so as not to add to her suffering, a geture that’s both helpful and unhelpful.
Even though her exemplar Kazuma watches her like a hawk, he’s still caught off-guard when blight suddenly appears on Bishamon’s neck. He acts quickly and decisively, gathering all regalia for a full-body inspection to ascertain who gave Bishamon the blight. When Dr. Kugaha performs the examinations and finds no blight, and Bishamon shows up with no blight on her neck, Kazuma is confused and his confidence shaken.
And that’s probably also Kugaha’s doing: the guy’s a doctor; maybe he faked the blight to stir Kazuma up? It would seem he’s poking and prodding at the weak spots of his fellow regalia. Suzuha was only the first. As he remarks to Nora (who the bad guys always seem to consort with on this show), Kugaha doesn’t consider Bishamon worthy of being the War God, is acting to topple her, and seems bent on using Yato to facilitate that outcome.