From what I remember, humans began turning into monsters that would suck up your soul. Authorities from around the world created a domed-protected city where the rich can live without the dangers of the outside world. The protagonist hunts these beings outside the city and he works with a scientist to find his lost sister. Anyway, a white-haired guy who was believed to have created the monsters awakened. And that’s all I read until I dropped it. Please help!
All I know about manhwa with the same art as Noblesse is Ability. It's in fact made by the exact same author and artist as Noblesse, there's a character with white hair too, but no dome city so maybe this is not what you're looking for. Been a while since I last read it though and it has a good premise, but sadly it's canceled
I think it sounds more similiar to Bleach, with the whole soul sucking monster bit, just minus the soul reapers.
Oh yeah, that was a good story, with people who got supernatural powers, and vampires (the white hair character) and werewolves and so forth. Doesn't seems to be the story OP is looking for, the protagonist of ability got a healing ability and wanted to maintain his grandfather's cafe while discovering all the hidden dangers around him amd getting involved with the supernatural power people organisation, which boss was a little girl. And the white hair vampire is a very dangerous guy who wants MC's ability and becomes his teacher and at some points becomes fond of him.
This should be it!! Haven't read season 3 as I was waiting for too long and I still remember the cliffhanger at the end of season 2... Ahh the good ol days of early days webtoons, I kinda miss them with their original story ideas