Bittersweet
Armin Arlert walked into the home that he and his wife, Sasha Blouse, had brought together three years ago. Everything was good now, despite the fact Eren had died, the Titans were gone, peace negotiations with Marley were going better than a lot of people expected, and Armin was respected as the head of those peace negotiations. Everything seemed to be going well, but when Armin got to the bedroom he shared with Sasha, all those good things stopped mattering as the images of their first time in Liberio came flooding back into his mind.
It was hard for Armin to enjoy all the fruits of his work in the Survey Corps as he remembered that his wife of only a couple of years, Sasha Blouse, was dead. While they were trying to rescue Armin's friend and the holder of the Attack Titan, Eren Yeager, from Marley, one of the young Marley Warriors, Gabi Braun, shot and killed Sasha with a rifle while the Survey Corps were making their escape in a blimp. Armin tried everything to keep her alive until they got back to Paradis, but it was too late. Sasha bled to death, and right then, it felt like Armin had died too.
When Sasha was buried back in Paradis, Armin was angry. Armin was angry at Eren for putting the Survey Corps in this dangerous situation in the first place. Armin was angry at that Gabi girl for shooting Sasha in the first place. Armin was angry at himself and the other Survey Corps members for not doing anything to save Sasha. Armin was even angry enough to brawl with Floch when Floch called Sasha a 'martyr for the cause'. Armin almost didn't want to help Paradis, seeing no reason to help now that his parents, Grandfather, and wife were all dead. However, after a heart-to-heart with Mikasa, Armin thought about what he was doing and decided to save Paradis, so that no other family had to bury the body of their child and to make sure that no other husband would have to bury their wife so early into their relationship.
Now that everything was over, Armin felt like collapsing, as he really had nothing to live for. The members of the Survey Corps, even Mikasa, had gone their separate ways, and they rarely talked. Armin had, at this point, been reduced to a shell of his former self, not smiling or really even pretending to care what went on around him. Armin was on autopilot at this point, just going through the motions of the day, with occasional bouts of guilt and regret taking him over, and Armin would hole himself into his room and do nothing but cry and mourn Sasha's death like he did when he first learned about it over the darkened skies of Liberio.
However, before Armin could once again bawl over his deceased wife, he heard the door to his home open. When Armin saw who was at the door, his heart dropped, as he saw Sasha's father, Artur Blouse at the doorway. Armin had been terrified to see Sasha's family alone after she was killed, especially since Armin had promised Sasha's family that he would protect her with his whole being, and he couldn't even stop a child almost ten years younger than him from shooting her. Sure, Armin was there at Sasha's funeral and saw when Artur confronted Gabi for killing Sasha, but he never felt comfortable or worthy of being alone with any member of Sasha's family.
When Armin saw the completely unreadable look on Artur's face, he closed his eyes, expecting an ass-kicking that he always figured Artur would give him once he found out about his daughter. When Armin saw how sad and pained Artur and the rest of the Blouse family had been due to the loss of his only child, Armin thought he shouldn't be allowed around them. However, while Armin was drowning in his self-loathing thoughts, he felt a pair of arms around him, and when he opened his eyes to investigate, Armin was shocked to see that Artur was actually hugging him. Armin was so shocked at the display of affection that he stood stiff while Artur ran his free hand up and down Armin's back to try and calm him down.
"Armin, none of this was ever your fault. You did your best to take care of my daughter, even up until her death, and I can never thank you enough for that," Artur said. And just like that, the dam burst as Armin wrapped his arms around Artur and began crying into Artur's shoulders. After isolating himself out of guilt for so long, Armin couldn't begin to express the feeling of having all the weight and pressure from the guilt he had been feeling over his wife's death slowly leave his body. As he and Artur continued embracing each other, Armin realized that maybe he had a chance to finally be happy again, and move on to the next phase of his life.