As Mirai sacrifices herself, does this mean that she defeated the ultimate youmu? No since Miroku has something up his sleeves.
As Akihito regains consciousness, it’s understandable to see why he would be upset because Mirai spares him while luring the ultimate youmu out of his body. Besides being part of a cursed bloodline, she feels that he still can live a normal life as seen in her emotional cell message. While this sounds depressing, at the same time, she also acknowledges that Akihito made her life meaningful. This is reason why she decided to isolate the ultimate youmu using her blood so she to finish it off. Of course, this also means that she is still alive when Akihito’s mother broke the news to him.
While it’s sad to see Akihito look so depressed, at the same time, I think that Izumi’s disregard to morals and feelings towards Mirai’s disappearance can be compared to characters like Kyubey and Kitsugu. Not only that, Izumi pretty much receives the same reactions from Hiroomi and Mitsuki being outraged just like Kyubey did when he revealed that he puts the girl’s souls in soul gems. However, there are some clear differences. She manipulates people (Mirai in this case) to kill Akihito in order to achieve her goal of saving the world rather than doing it all by herself. Thankfully, her intensions aren’t evil compared to Miroku, who wants the world for himself.
From the last few episodes, my feelings towards this show has changed. While Akihito’s glasses fetish still bothers some people, this and the last episode shows that perhaps we shouldn’t have judge the show too quickly as there might be an interesting and/or serious twist. While I can admit that Kyoto Animation focused a bit too much on comedy, which overshadowed the dark aspects of the show, hopefully the finale will be just as exciting when Akihito reunites with Mirai and defeat the ultimate youmu once and for all with 1/4th of the Ultimate Youmu’s power. Not only that, I also want to see Izumi curb-stomping Miroku for causing this mess, although I doubt we’ll see this.