The problem with making a deal with the devil is that he always wants his due. That's at the base of folktales from every culture, and the 2018 reboot of Shigeru Mizuki's GeGeGe no Kitarō is more than prepared to put its own twist on it as the Four Demon Generals arc comes to its close. As time begins to run out for Kitaro to deliver the missing yokai to Enma-O, his stress begins to show in the ways he interacts with the rest of the world, causing him to twice get possessed and allowing Rat Man to fall to even greater depths with Kitaro distracted. Although none of this is explicitly stated, the sheer amount of stress that Kitaro is under allows for this set of episodes to be, if not darker than before, at least heavier.

Not that the series has ever shied away from tackling heavier themes. Episode twenty stands out as a prime example of this as it handles Japan's involvement in World War Two and the impact on its citizens and soldiers. There are echoes of that in the final episodes of this arc, when Tamamo-no-Mae, a nine-tailed fox considered to be one of the three most evil yokai in Japanese mythology, tries to start another war: while Kitaro and the others are trying to get her soul back to Enma-O and thwart her takeover of the underworld, Rat Man goes right to the humans she's manipulating. He says that he hasn't been so afraid in eighty years (i.e. World War Two) and at one point yells that he can't face another war. Although he's usually the (generally rotten) trickster figure of Kitaro's internal mythology, in this case he serves a bigger purpose – he's the embodiment of the wartime survivor, the veteran who remembers and won't let people who don't get away with carelessly causing the same damage again. This is a major shift in his character, and it can be seen as giving him a reason for being who and how he is, although we should note that it's not an excuse.

That last is important because Rat Man gets up to some of his worst tricks here, pushing his relationship with Kitaro to the breaking point. Whether he thinks he can get away with it because of what Kitaro is doing for Cat Girl (and by extension Mana) is unclear, but his work with the Suiko, a kappa-adjacent soul-sucking water goblin, in episode sixty-four is horrific. This particular episode is also one of several in this cour that specifically showcases the awful ways revenge can go wrong or turn on the person seeking it. The housewife in the Suiko storyline is bitter and angry, but her use of the Suiko's powers becomes a monkey's paw, depriving her of the people she loves as well as punishing those she hates. The social media star of episode sixty-seven destroys her own life in pursuit of revenge upon the people who “robbed” her of her fame, and episode seventy-three is an almost literal retelling of W. W. Jacobs' 1902 story “The Monkey's Paw,” with the legendary dragon Yamato-no-Orochi taking the place of the animal's foot and proving that more wishes only give you more chances to destroy yourself.

But perhaps the most important use of this theme comes at the end of the story arc, when Mana has a run-in with one of the Generals, Ibukimaru. Ibukimaru, she learns, was a kind yokai who was married to a human woman he loved. When she was killed, he turned against humanity and ultimately destroyed his soul (or rather corrupted it) with his mindless pursuit of revenge. Essentially, he did what Rei is attempting to do – kill everyone who may have participated in the destruction of his family. In the end all it brought Ibukimaru was unhappiness and deprived the spirit of his wife her eternal rest, something he comes to understand over the course of episode sixty-nine. He then is able to take on the role Kitaro more often plays, warning Rei about the path he's on and ultimately coming, at Mana's urging, to help bring things back to the way they ought to be. Ibukimaru is the hope of redemption, teaching the lesson that both Rei and Kitaro (whose determination to go it alone has ended up causing more pain and grief than he realized) that there are better ways to do things, and that giving in to darker emotions is rarely the answer. It's something Rat Man has had the opportunity to learn multiple times and hasn't yet, a lesson Mana and Cat Girl figured out in earlier arcs. It's also the one thing that both Rei and Kitaro very much need to know right at this moment.

This arc, and these episodes specifically, have presented us with a much more vulnerable Kitaro than we've seen before. He falls victim to the possession of both Mabyo and Iyami, he fumbles with his handling of his task from Enma-O, and he allows his fears of losing Cat Girl and the effect that will have on Mana to affect his work more than even the events of the Western Yokai arc did. It's a good change in terms of his character development, although it also may be behind the fact that we get more “scary Kitaro” episodes this time around as well – can't forget that he's not always nice when he's being helpful, now, can we? Overall, however, he's in a much better place to begin the new Nurarihyon storyline: still Kitaro, but a Kitaro who now appreciates that strong as he is on his own, letting others in helps to make him even more formidable.