The final episode begins with a flashback to when Gutoku first met Airi: she impaled him on her claw. When he awoke, Airi appeared human to him again, and he seemed to be healed.
Back in the present, Ichiya and the others are prepared to do battle against Gutoku, until Aoi activates her World. We already knew that it enabled communication between people, but it can also prevent others from using their World powers. Aoi steps over to Gutoku’s side permanently, leaving behind her peers for good.
Gutoku whispers something to Aoi and she takes off, with Asuha and Canaria hot on her heels. Gutoku gets into a fistfight with Ichiya, but when he stops one of Kasumi’s bullets with his hands, he transforms and reveals he’s half-Unknown. Perhaps this is the result of Airi infecting him when she injured him; the cause of his mutation is not specified.
Meanwhile Asuha catches up with Aoi, and the two girls get into a fistfight. The fight serves as a reminder that Aoi is not as useless as she’s been portrayed 
throughout the series – she was Maihime’s backup until Hotaru showed up, after all. Aoi also mentions that her World allows her to basically read Asuha’s mind when they’re face to face. Eventually Aoi manages to almost choke Asuha out, but Asuha turns the tables around and gets the upper hand on Aoi.
Elsewhere in the tower, Maihime and Hotaru are facing off against Airi in her true Unknown form. She’s a strong foe, probably the strongest Maihime has ever faced. Maihime and Hotaru’s fight with Airi ends as Maihime impales Airi on her energy sword. Just before she dies Maihime remembers a conversation she had with Airi when she was a child, and Airi talked about wanting to experience having a baby and dying a satisfying death. Maihime flashes back to the present and she realizes that she has been fighting Airi all along. This is confirmed once Airi’s body disintegrates and Maihime spots the pocketwatch on the ground. However there is no time to grieve yet – Maihime and Hotaru must rescue the remaining children from cold sleep.
As all of these fights are going on, Canaria has gotten herself lost chasing after Asuha and Aoi. However she spots the dimensional gate, and once she reaches the top of the tower, she activates her World and begins singing her song.
Everyone else hears Canaria’s song and is boosted by its effects. Ichiya fights back against Gutoku, who had pinned Kasumi and Ichiya against the wall with a blasting stream of energy. Gutoku reveals that Airi has died and that the tower, which was Airi’s own body, will soon crumble and the dimensional gate will fail. Gutoku closes his eyes and Ichiya’s gravity powers blow a hole through the side of the tower.
Ichiya wastes no time telling Kasumi and Asuha to flee the tower, as he flies off to find Canaria. He finds her in freefall and he saves her in the nick of time. Once everyone is assembled outside the Administration tower, Ichiya and the others join the rescued cold sleep kids in watching the tower fall to the ground.
However inside the tower, something is happening. A severely injured Gutoku finds Aoi’s unconscious body, and then Airi’s spirit appears and asks him to take care of Aoi. Airi knows that losing two parents at once would be too much for Aoi to handle. Gutoku agrees to take care of Aoi.
Ichiya and Canaria meet with Johannes, and tell her that they want to rebuild Tokyo before they leave to see their parents. Then Kasumi and Asuha rush in to visit with their mother, and Ichiya and Canaria leave to give them some privacy.
By the seaside, Hotaru and Maihime stand at Aoi’s grave marker. They discuss how Airi was kind like a human mother would be, and Maihime admits she still doesn’t fully understand the conversation she had with Airi in her past. Then they’re joined by the other four representatives, and Kasumi reveals that he and Asuha are leaving. The other four will remain behind and work to rebuild their cities.
After the credits roll, Canaria’s voiceover says that the story is about learning more about their World powers and how they can be used to save the world.
My thoughts: I thought the memory of Maihime and Airi talking was a nice touch and helped tie in with the family theme of the previous episode. In the end Airi never birthed a child created from hers and Gutoku’s genetics, but Maihime was probably as close to having a child of her own as she got, and Aoi definitely saw Airi and Gutoku as her parental figures. So in a sense, in the end Airi did sort of have a child, and she was something of a parent.
I wonder if we will get another season. Maybe a storyline that takes place after a timeskip, when Gutoku has been raising Airi for a period of time? Maybe there’s a battle between countries over the kids who have World powers?
Lastly while I don’t want to whine about graphics and animation yet again, I feel like I have to mention how disappointed I was with the quality of animation in this episode. The series had been getting slowly worse as we got closer to the end, but I feel like this episode took a sharp decline in quality. Much of the animation was derpy, like it was rushed and there was simply no time to get a lot of the proportions right.
Final Impression
Story: Absolutely fantastic. If you’d told me at the beginning of the season that this would be a story about aliens abducting children and brainwashing them to fight mankind, I would’ve told you that you were nuts. Qualidea Code had some of the biggest twists I can remember seeing in an anime in recent years, and I am still so impressed with the plot of this show, even if it was somewhat hindered by poor animation.
Characters: I’m kinda meh on the cast. Maihime’s probably my favourite character, but I have issues with most of the others. Airi and Gutoku were also very interesting to me, especially once it was revealed that Airi was an Unknown and Gutoku loved her despite being half-human himself.
Random list of thoughts: Ichiya was too arrogant for my liking, Kasumi was too apathetic, and the brother-sister complex between Kasumi and Asuha kinda weirded me out. Canaria was cute but a little too vapid for my liking. Johannes was far too childlike, but that was also part of her appeal, and I love how Kasumi was just having none of her ego-stroking. I did like that Asuha eventually accepted Johannes once she got used to having her biological mother back in her life. Aoi became infinitely more interesting to me in this episode, and I honestly wish her betrayal had happened an episode or two ago so there was more time to feel 
the resulting pain from her decision.
Music and Animation: The music in Qualidea Code was pretty awesome. There was a couple of opening and ending themes used throughout the season, which always helps to keep things fresh. I liked the electronic-sounding themes used during some of the larger fight scenes, and Canaria’s World song was pretty to listen to without it getting repetitive.
However, in terms of the animation… I’m really disappointed. The animation was so pretty in the first half of the season, but the latter half was pretty disheartening. Faces were not proportioned right, limbs looked off, and just blah.
Overall Thoughts: Honestly, like with Berserk (2016), the only issue I have with this show is the quality of the animation. The difference is that it was known from the beginning that Berserk would be using a mix of 2D and 3D animation, and it was clear pretty quick that viewers would either love or hate it. Qualidea Code started off with stellar animation, but experienced a decrease in quality for the last six or so episodes.
And the final episode in particular was really atrocious. The example that sticks out in my mind was the fight scene between Aoi and Asuha. Faces were off, limbs were everywhere, and the whole thing just looked really warped. For the poor animation in the last episode alone, I’m taking off an extra half a point. I don’t know why the quality suffered so much, but I’m curious whether anyone else noticed a change too. Or am I really just too picky?
Final Score: 8.5/10