@Passiflora-C

That's a big list. But yeah, if there's any series you like that aren't in the suggestions forum already, just add them in. And if some already have posts, you can post in them to just say you like the concept.

As for Zilbagias... I'll be completely honest, I didn't know anything about the series when I recommended it. I just saw its cover in the JNC discord and thought "it's the Kumo Desu Ga artist, so I might as well try it out." And what did you know, it worked.

My top three favorite light novel themes are villainess protagonist, demon king protagonist, and light novel with educational elements in them (like military tactics/strategy, economics, and public administration). J-Club already has a number of them and God praise you for it. The first two thrill me with characters not allowing their titles to dictate their lives, and the last make learning usually boring subjects fun. Some great picks would be:

Milady Wants to Relax

I Will be a Villainess Who Will Go Down in History

Maoyuu/Be Mine Hero! I Refuse! (the manga is licensed but not the novel)

Demon King Urban Development! The Strongest Dungeon Is An Urban City

San Tairiku Eiyuuki/Hero of the Three Continents

Isekai Kenkokuki/Otherworld Nation Founding Chronicles

However, there are two stories that I would throw all my current novels, and manga; novels and comics both Japan and Western (minus the Bible) to read.

A Dark Rabbit Has Seven Lives

&

Id-The Greatest Fantasy Fusion (Korean)

These are not well known. However, they also the most underrated stories I’ve ever come across and I’ve read a lot. The first is a heart throbbing fantasy-romance with constant thrills and suspense. I’ve watched the anime on Crunchyroll so many times I’ve memorized all the lines. I always watch with bated breath praying the protagonists’ love will overcome a world that refuses to let them to be together.

Id is a masterpiece fusing Korean and Western fantasy themes. It has action, adventure, fantasy, comedy, romance, and a hint of tragedy. The plot is very original, the protagonist (Id) is isekaied from his Korean-Fantasy home world to a Western-Fantasy themed world. He carries with him a magic sword inhabited by a female spirit. He then meets a female elf whom he develops a romantic relationship with. The girl sword is also in love with Id. She watches jealousy as Id and the elf grow close. Tragically, she can do nothing because since she does not possess a physical body, her love will never come to fruition. All the while she must support Id as he is forced to fight power-hungry nobles, mad magicians, evil gods, and warriors who possess enough power to destroy nations single handed. All the while he is constantly mistaken as a girl because he’s too beautiful! Even fighting a battle in a dress!

Id was very well received selling over hundred thousand copies. Sadly the publishing company went bankrupt because its other novels and comics were poorly received. Last I checked the author was still active, but saying his progress has slowed to a crawl would be an understatement. Every night, for nearly ten years, I’ve literally prayed to God that they would be revived. I guarantee if J-Club requested and got permission to publish, it would be well received; attention would be drawn to it again and the author will be inspired to continue his great work. I would even be willing to help translate and edit it full time free of charge, and
in my will leave everything I own to J-Club.

A Dark Rabbit Has Seven Lives is the most epic romance any I've ever watched. I've watched it so much I've memorized every scene. Here is a link to a trailer: https://www.youtube.com/watch?v=8BnZ5C15OHE
ADHSL also has great reviews on Baka Updates: https://www.mangaupdates.com/series/a9ctj23/itsuka-tenma-no-kuro-usagi-novel
I'd cry tears of joy if someone licensed the novel for translation.
Main character catchphrase: “I’ll die seven times for sake.”