The first 20 chapters take place before canon, so we know more about Loki, his personality, his interaction with his family and his lovers(only 2), how he got his powers since he's more powerful than the original Loki but not extremely OP.
I don't think mc will become a king since he more of a scientist, who wants to reach the apex of power that the world can offer so this option is out(not sure if the author has other plans).
FINALLY, I want to say this is an enjoyable story and it's the author "first work"