So since there isn't a definitive definition of Loki and what he stands for, he is very hard to understand so no one exactly knows his origin or his depiction, so i'm just going to mix my marvel knowledge with my norse knowledge to describe him.

So Loki is most commenly seen as the Trickster god of lies and deception. He was (in the marvel universe) adopted by Odin Odinson, which makes Loki an unofficial brother of Thor Odinson.

Loki plays a huge role in Ragnarök (an event in which everything that exists, stops to exist and where the 9 realms will reborn). Because some of his children (Jörmungandr and Fenrir) a giant serpent and a wolf will kill some of the gods of asgard.