I think like everthing else there's bad thing and good things in the industry.
You can always find thing you like or just don't like it in general and that's fine. Me personally have completed like less than 10 series and way more I haven't finished. reply
Mangakas: Kuroi Yodaka, Tobi Washio and Haji. {honorable mentions NAONO Bohra, Akabeko and Kumaneko}
Manhwagas: Upi, Jung Seokchan and Brothers without a tomorrow {honorable mentions Niji and Ma Jeung Ji} reply
