Yusa was the creator of the world and was born with it, Alexei was the second god created by Yusa's frustration at the first human race which tried to kill her to steal her power causing her to freeze them all.
Yeah, it was mentioned he is a gang leader, he's actually from the south and mikan's mother is northern but her father really hated her and her mother so he waged war on the entire north Because he knew people didn't like the north and when he started the war effort he said anyone who kills Mikan's friends will get a special position so when the Antigrants saw him in the park they knew they were gonna kill him
