Loki grew up with a passion for mischief and magic as the younger prince of Asgard. Upon discovering that Odin adopted him as an infant of Asgard's sworn enemy, he turned murderous, wanting to prove that he is as good as his Thor. Failing that, he turned his back on his entire family (and his lover Aaernia) and attacked Thor's beloved Earth to subjugate it. In the process, he killed hundreds or thousands of people before Thor and Earth's mightiest heroes captured him. Now, Thor has dragged Loki back to Asgard gagged and chained to face justice, likely execution. He is a compulsive liar, and is often referred to as having a silver tongue.

Loki appears at two different ages, which argue with each other. The main Loki is the older, a bitter but still extremely mischievous man. The other is a version of him from before he discovered his true heritage; a young, bright-eyed man on the cusp of adulthood. For the sake of easy clarity, the two voices need to be immediately recognizable as distinct, but as the same person. The goal is to cast the same person for both, but if necessary, the two different versions of Loki may be cast separately.

Loki's voice is laden with mischievous intent. He can be extremely seductive with ease, or intimidating at the drop of a hat. Older Loki is violent, masking bitterness and defensiveness. Younger Loki is more vulnerable. It is preferred he have a British accent, or something similar.