Us. Thor used it unconsciously. Mother told us those stories. For his whole life it had been us. Never just Thor or Loki, always Thor and Loki.
When he thought about it, Thor realized it was his own way of remembering the Loki he had grown up with. It was his way of keeping Loki with him.
Thor had come to the dark world expecting the good chance that at least one of them would not be leaving, but he had expected it to be Jane or him.
Loki was a survivor. It wasn’t in his nature not to come back from battle.
Loki had done unforgivable things, there was no denying, and part of Thor believed that he could never forgive his foster brother, but he was still his brother. Spend your entire childhood and beyond with someone constantly at your side, and it seems like they are part of what makes you yourself.
The phrase ‘lose a part of yourself’ is thrown around so casually, as if it were something commonplace that everyone felt at some point, but the true gravity of something that was in integral part the way you became who you are is so much more than just a phrase. It wrenches your very soul apart in a way you didn’t think possible.
Loki was as much a part of Thor as his hammer was. He may have proclaimed loosing hope that he could ever trust Loki again, but even if he didn’t trust Loki, they would always be brothers.
Not to say that it hadn’t felt like someone ripped him in half when Thor watched Loki let go of his hammer and fall into the void with that brokenly hopeless expression on his face, but this was worse. Just when the slightest hope of redemption had begun to grow in Thor’s heart, even if he had tried to ignore it, the already remote possibility of Loki’s return to him had become an impossibility.
That’s the thing about death. It doesn’t just erase their presence from your life, it erases all the things that they could have done. It just ends their potential to do good or evil.
It hadn’t surprise Thor when he would unconsciously call Loki brother. Even Loki stopped getting that flash of rage and hurt in his eyes when Thor called him that, because even he knew deep down that there was no Loki without Thor, and no Thor without Loki.