I believe he was cursed during the battle by a spell that forces the victim to show their true emotions, and everyone expected him to go on a bloody rampage, but instead he just broke down crying in the most heartbreaking way leaving all the Avengers stunned at the fact that they were all watching a God cry.
Each "chapter" showed the scene from a different Avengers point of view where you follow their inner thoughts in the situation and it was absolutely beautiful. Nothing much happened really, but the way each Avenger experiences the crying god differently left me in awe.
I think it ended with Tony hugging Loki.
Please help me find this story again, please?