Loki

Loki Laufeyson is a major character in the Marvel Cinematic Universe and the Thor trilogy.

Background
Loki was born on Jotunheim during the war of the Asgardians and the Frost Giants. As an infant, Loki was abandoned in a temple by his father Laufey, who left him to die because of his small size for a Friday Giant. Odin Borson found Loki and adopted the infant Loki. Though raised alongside his adoptive brother, Thor, Loki felt he was in the shadow of his older brother and mostly got along with his adoptive mother, Frigga, who taught him magic.

Personality
Loki is initially portrayed as power-hungry and uncaring and villainous. However, he is notably less boisterous as Thor is, being more quiet than his brother. This was evident when he did not rage like Thor did when their father was investigating how the Frost Giants entered Asgard. He felt jealous and overshadowed of Thor, whom their father showed more favoritism towards.

He usually had no care for humanity, seeing it as a weakness and even bullying Thor about it. However, due to being manipulated by the Mind Stone, Loki was influenced by its terrible effect when holding it. The only human he ever feared was Bruce Banner when he was the Hulk, often traumatized from the event when the Hulk smashed Loki on the floor and called him a "puny god" back at the Battle of New York.

Despite his deceitful nature, Loki did care a great deal about his adoptive family especially towards his mother, Frigga, whom he was close too. She taught him magic while Thor was taught to be a warrior by their father. Also, instead of killing Odin, he merely wiped his memory of being the King of Asgard and left him at a retirement home. He and Thor eventually fully reconciled after a thousand year grudge in Thor Ragnarok, and could not bare to watch Thor being tortured by Thanos that he would willingly give up the Tesseract to save his brother.