Gates of Summer - S2.E24

After having a brief encounter with the phased-out Eureka, Renton sets with Ao to Iwato-Jima where he thanks Toshio for taking care of his family and then decides to make use of the Quartz Gun to destroy the original Scub Coral at his timeline and prevent it from spreading itself throughout the dimensions. As Ao confronts him to stop it, he learns that surprisingly, Truth has not fully disappeared, but has become the Nirvash Neo's archtype instead. Ao then decides to make use of the Gun's last shot to change Eureka's fate and have her reunited with Renton. Because of it, Ao is transported to the year 2027 where he bids farewell to Truth and returns to Iwato-Jima to resume with his life, despite the fact that there's a chance that no one in the world remembers about him anymore.