As someone whose favorite episode so far is probably still 15, I also feel this episode, and a lot of this overall storyline so far, go against it, but that's also exactly why I think it's building on that stuff in an interesting way? Baku made a big decision in each of those episodes -- facing the truth of who he is and choosing to spare NOX -- and the plots since have gone out of their way to further interrogate that and challenge Baku to deal with escalating complications resulting from those choices. Those choices end up flipped completely upside-down by this episode, but I think that's also the next question Baku is being asked by the narrative -- what is it that makes a choice worth standing by?

Another thing worth noting is that, on the slightly more meta level, that *is* still the climactic point in the two-parter formula where Seven locks in and takes down the Nightmare to stop it from doing further harm? Which is also the point of invoking the usual routine of heading out on the bike, too, and why I think that creates an episode that's a little more rich emotionally. Rather than emphasize the tragic angle the entire time, the show allows you the option to sort of lose yourself in Baku's waking dream, the way he's actively trying to lose himself, before the actual fight with Catastrom happens with its more ominous new BGM and we see "Seven" clearly shaken by the destruction his new power has caused.

Much like what I said about NOX fighting Six and Five a few episodes back, I don't think it's necessarily a problem which specific way you feel about what's happening, because to begin with, the show isn't trying to insist that there's only one correct way to feel.

I haven't ever had the chance to mention how much I love the running gag of the barking dogs in the background whenever they're climbing up there, so let me take this opportunity to say that my new headcanon to explain this is that the neighborhood animals all hate Fujimi so much at this point for sneaking around like a criminal that he thinks he has to sneak around like a criminal to avoid being chased by dogs. It's a vicious cycle! :p