So, there are 3 things I see when looking for a new series to read: title, cover and blurb/synopsis.
The title is kinda odd. Maybe try changing the title from 'Specter days.' to 'Specter Days'. The period at the end and the lack of proper capitalization may rub some (possible new) readers...
If your story involves harem and follow the rules of the sub, you could always try r/haremfantasynovels on Reddit.
Or if it involves game systems and all that RPG stuff, you could try r/LitRPG on there too.
If you have a Kindle Unlimited subscription, I recommend you to check out r/haremfantasynovels on Reddit. It's a community focused on western harem.
If not, then I recommend these novels:
The Mook Maker;
Reformed Villain’s Redemption in the Reversed World;
Wisher Beware and its sequel Ecdysis...