As a result of Odin’s death in Thor: Ragnarok, fans have speculated why Loki’s appearance remained Asgardian even after Odin’s original link to Asgard was severed. Loki has had a complicated storyline throughout the MCU, transitioning roles between villain, hero, and antihero, particularly in his recent Disney+ series, Loki. However, Loki’s story began in 2011 when Thor first encountered him. It was revealed in this film that Loki, a Frost Giant born in Jotunheim to Odin and Frigga, the king and queen of Asgard, was adopted by them.
Odin reveals that he discovered Loki as a baby in Jotunheim in a flashback in Thor. He had been left behind by his father, Laufey, the Frost Giant King and a fierce adversary of Odin. Loki’s skin and eyes were initially blue and red, like other Frost Giants, despite his small stature. His appearance changed to that of an Asgardian after Odin picked him up.
Because of this, in Thor: Ragnarok, viewers have wondered why Loki didn’t turn blue after Odin’s death. If Loki’s appearance changed because he contacted Odin, he should have reverted to his original state after that relationship was broken. Loki didn’t turn blue because he never had blue skin throughout the rest of Thor: Ragnarok and until he died in Avengers: Infinity War. One theory on Quora describes this by claiming that Odin’s magic, which was so strong that it lasted after he died, caused Loki’s appearance.
This theory claims that Odin used magic to make Loki appear to be Asgardian, citing Marvel’s Visual Dictionary. On the other hand, Odin must have employed a more potent form of magic. When he entered the TVA Office, Loki would have turned blue because magic and powers did not work there. So, Odin must have cast a formal spell on Loki. This didn’t need to be constantly maintained by the god of lightning. Loki only regained his blue skin if he touched a Frost Giant or one of their artifacts after the spell was cast. Due to Loki’s appearance being a spell, not just an optical illusion, Odin’s death could not reverse or break it.
There is precedent in the MCU for the idea that a spell can continue after its caster dies. Thanos’ henchwoman Ebony Maw attempted to steal the Eye of Agamotto, an Infinity Stone, from Dr. Strange in Avengers: Infinity War. As it turned out, Dr. Strange’s spell kept Maw from getting her hands on the Infinity Stone. He further explained that his spell would safeguard the Eye of Agamotto even after his death. It was the same with Loki. Odin had cast a spell on the Loki. This prevented him from reverting to his original skin color, even after Odin’s death.