My Girlfriend is the Nether King

Good premise, horrendous execution. An unlikable mc beyond Grid from Overgeared's early chapters... and there's no sign of him improving.

how can someone design such an unlikeable MC?

interesting title, but started with too despicable character (read: psychopath).. a bully teenager, turned into stalker, and then assaulting ex-girlfriend, with slow-to-none personality improvement.. makes it hard to like MC and can be a struggle to read the first 8-9 chapters..