These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Complete Monster: The Fake Ryuubi he takes Riri a kid hostage and threatened Kouchuu to commit assassination whats worst he leaves innocent people behind to die just for fame and glory
Crowning Moment of Heartwarming: In the original game with Sousou, the key Wei generals and strategists at his mercy, Kakouton and Kakouen assume that a statement from Kazuto signals that their execution has been scheduled. Rather than bargain for their lives, both of them beg Kazuto to spare Kyocho out of their set of True Companions. Their reasoning is while all of them would gladly follow Sousou to their deaths, Kyocho is still young, barely a teenager, and has many years ahead of her yet.
Nightmare Fuel — You may be at least a bit squeamish at Bachou's appearance in episode eleven of season one...
Or anything Chousen and Himiko...really...
Player Punch - An almost literal application for those who played the games and then get into the anime. For example Kayuu keeps saying that she's the type who lives a long life while players know she dies in almost all the scenarios and Sonsaku expressing the fact that she doesn't know what would happen if she or Shuyuu lost each other. We do. Shuyuu would eventually have what amounts to a nervous breakdown, cause a civil war in Koutou instigated by Ukitsu and commit suicide by burning down the palace. Plus becoming a much more bitter and cruel woman than the one we know from the anime.
Villain Decay — Ukitsu started off as seemingly invincible, only to be killed by Ryuubi of all people later on! Choujou also seemed very powerful and influential, but it turned out that she was just being used by Ukitsu, who ended up turning her into a rat.
And the biggest waste of villain potential throughout the course of the series has to be the masked, cloaked man from episode 8 of season 1. He orchestrated a successful kidnapping, and subsequently an almost successful assassination attempt. He resurfaces later on, but is unfortunately revealed to be the Fake Ryuubi. His decay is so drastic, that it's almost impossible to imagine that the two are in fact the same person.