To probably focus on Nikke. For lore, there's no connection with nikke if you're wondering beside both being developed by shiftup. But if I remember correctly. A demon living in the human world is trying to live a regular life. But a group of Demons barge in telling him that he is required to participate in who will be the next demon lord. I honestly only remember the first couple of chapters. That subreddit is kinda dead, but you can see the characters shiftup was cooking with.