I can read these mangas many times! I rate them >9.5/10 based on my own preferences, so there will be lots of non-mainstream BL
Genres: NO PWP, no doujinshi
Length: <100 chapters or 3 vols
Search by tags: http://www.mangago.me/home/people/12706/manga/1/
If you like this list, please click "RECOMMEND". Thank you XD
2nd list: http://www.mangago.me/home/mangalist/655038/
(IF 1ST LIST IS FULL, I'LL MOVE OLDER ONES TO MY 2ND LIST)
Long series: http://www.mangago.me/home/mangalist/645867/
This list is not exclusively isekai.
(transmigration, reincarnation, regression)
May include:
Heroes and demon kings
Magic and/or magical creatures
Dungeons and towers
Zombie apocalypse
NEW LIST FOR: VILLAINESS / OTOME
https://www.mangago.me/home/mangalist/3113737/
May or may not include harem (mostly not).
Will SLOWLY rate one by one.