Online platforms like Amazon or Barnes & Noble's website are good places to start. They usually have a wide range of light novels available. You can search for 'leviathan of covalent light novel' on their search bars. Also, some specialized Japanese or Asian literature websites might carry it as well.
Since I don't have direct knowledge of this light novel, it might be about a leviathan - like being that is connected to covalent in an unexpected way. It could be that covalent represents a form of power, a force that binds things together in the story's universe, and the leviathan is either a creation of this covalent force or is in some way fighting against it. Maybe there are characters who are trying to understand or control the leviathan using covalent - related knowledge.
You could try searching on popular fanfic websites like Archive of Our Own or FanFiction.net.
One option could be to search on dedicated manhwa websites. Some well-known ones are Manganelo or Kissmanga. But be careful of potential ads and the legality of the source.
Well, another place to look could be some anime - related forums. There are often sections dedicated to fanfiction sharing. Members might have written or know of some great Highschool DxD Katerea Leviathan fanfictions. You can also ask for recommendations directly in those forums.
You can start by looking on popular fanfiction platforms like Archive of Our Own (AO3). It has a vast collection of fanfictions on various topics, including Leviathan Castiel and Dean. Just use the search function and type in relevant keywords. Another option could be Fanfiction.net, although AO3 generally has more diverse and inclusive content.
I'm not entirely sure as I haven't read it specifically. But generally, a light novel often has elements like interesting characters, a unique plot. It might be about a story where 'leviathan' is a central figure, perhaps a creature or a symbol in a fictional world filled with adventures, magic or some sort of complex relationships among the characters.
There are also some websites dedicated to free graphic novels. However, make sure they are legal. For example, Webtoon has a wide range of comics and sometimes graphic novels. You can search for 'Leviathan' there. But always be cautious about the legality and safety of the website.
Since I haven't read it, I can't say for sure who the main characters are. They could be young heroes on a quest, or perhaps scholars researching the leviathan.
I haven't read it in detail, but generally it might involve a story set in a fictional world with its own set of rules and characters. Maybe there are elements of adventure, magic or some sort of power struggle.
Yes, Leviathan can be a novel. It depends on the specific context or work you're referring to.