looking for a novel with sword and magic, sword masters, magicians, kingdoms, empires but it should be a serious one not cute not fluffy not comedy.
Maybe something like: Wortenia Senki Realist Demon King Realist Hero Arslan Senki (not sure 'bout the novel translation, though the original should have been completed long time ago) Grimgar of Fantasy and Ash (not sure 'bout the novel status, I've only followed it's anime) Lapis no Shinzou (translation just started +/- last month, not many ch yet atm) Animes/mangas: Berserk Claymore Vinland Saga If you don't mind fantasy w a bit more modern (+/- WW1/WW2) setting, then I'll recommend anime/manga ver of Youjo Senki
As long as you are okay with the MC not being the one to use the sword (he has a minion sword master for that), then I recommend Trash of the Count’s Family. The MC uses a global scale as he messes with kingdom’s and the empire both politically and militarily. The are lots of sword fights and magicians in this novel, as well as an excellent caste of Characters.