Now all I can think of is an AU where Odin kept Loki as a literal relic locked up with the other stolen Jotun things in the vault. One day, Thor and the Avengers finds a half-crazed Loki in there when researching the Tesseract.
Thor saw through his illusion. "Enough, Loki. No more illusions." ----- Extremely powerful scene in Thor Loki doesn't want anyone to see how heartbroken he is, but Thor knows.--This scene broke my heart