I complied some of my favs here. Please note that NONE (in numbers 0) of these works are truly finished. Also note that Except for Whatsawhizzer, all these webnovels can be packed into .epubs using things like Webtoepub(chrome extension))
Monstergirl hidden gems:
'Monsters and Maidens' by Ravnicrasol
'Wisher Beware' and book 2 'Ecdysis' by Snusmumriken
'Monstergirl Rancher' by Lasarus
'Monstrous Horizons' by Bruce Sentar (yes, the guy who is also responsible for actual non-hidden gems like 'Saving Supervillains' and 'Dragons Justice')
'Realm of Monsters' by Frostbird
"regular" Harem hidden gems:
'Getting Lucky' or 'Man of the House' by Whatsawhizzer (This Author has tons of good stuff; accessability is sadly mediocre)
sfw stuff:
'Double-Blind: A Modern LITRPG' by Eligos
'System Change' by SunriseCV or on Royal Road
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not entirely sure how welcome something like this is. I hope someone enjoys :).
It's commercial, but Bruce Sentar's: Saving Supervillains, is a supervillain turned superhero harem
https://www.amazon.com.au/gp/product/B09XCKT6D1
Saving Supervillains by Bruce Sentar was great.
A former villain is living a quiet life, hidden among the masses. Miles has one big secret: he might just be the most powerful super in existence.
Those days are behind him. But when a wounded young lady unable to control her superpower needs his help, she shatters his boring life, pulling him into the one place he least expected to be—the Bureau of Superheroes.
Now Miles has an opportunity to change the place he has always criticized as women flock to him, creating both opportunity and disaster.
He is about to do the strangest thing a Deputy Director of the Bureau has ever done: start saving Supervillains.
https://www.amazon.com/Saving-Supervillains-Bruce-Sentar-ebook/dp/B09XCKT6D1