Legend says they were blood brothers. Comics and the movies say he was Odin's adopted son.
The Son of the mask and Thor 2011 he has father issues.
Thor 2011 he feels inadequate as a son he's jealous of his brother Thor and wants his father to be proud of him but he goes about it the wrong way.
Loki in the son of the mask is always being tormented by his father Odin at the wrong times he's stripped of his powers and regains them. He uses Baldr Odin's son he later killed in legend as a distraction for Odin when he was tormenting him once.
