Wow, yeah with that revelation I can see why Jirou left the superhuman bureau. It is an explosive finale, all right, but it is also a mess. First, the things they did right, which is the Superhuman Bureau's past catching up to them and tying that to the Knight's story, and Jirou's admiration for the Knight. If this isn't a strong motivation for Jirou to leave, I don't know what is. Oh yeah, and his dad was involved in it, so... yeah anime dads keep being worst dads. Then there is Claude, a victim of human experimentation, and in an impassioned speech, he declares there is no justice. It's a powerful moment considering everything we know about who the "good guys" were turned upside down. In the end, the show, as it has been doing from the start, consistently highlights the complicated nature of conflicts.
But at the end of the episode, it sort of left me underwhelmed. Firstly, they should have revealed what was up with Kikko in episode 12 because let me tell you, her action in that episode left me more confused than intrigued. And it sort of amounted to nothing because when they recovered her I felt nothing. Secondly, the political theme is heavy handed. Think about it, the one cameo appearance from the immortal family happened because two of them needed to discuss the message behind what was happening. Was it really necessary in the middle of the action to cut to that conversation? I don't think so, and I don't know how relevant that conversation was. What else was the purpose of that Hiroshima scene at the end other than to bring in some unneeded political symbolism? I think sticking that in the end was unnecessary and should have been stuck in the next season when maybe they could develop the idea. Thirdly, it was a mess pacing wise. Things happened fast and then it feels like it increasingly sped up. The end happened so quickly that at the end I asked myself, "that's it?". It just felt like a series of cuts, and it happened all towards a nonsensical scene where everyone sings the kumbaya while some of the side characters go and help Jirou despite the fact that many of them had bad feelings on him. Anyways, the pacing completely undermines a lot of the emotional impact and doesn't leave any breathing room for reflection.