Honestly, this comes up a lot, and I always feel like I have to give the full disclaimer first: you really, really should consider the official routes. It might not be the 'download' people want to hear about, but the official English translation by Seven Seas is what supports the author, Kinu Shoko. They publish the light novels in physical and digital formats you can buy from retailers like Amazon Kindle, Google Play Books, or Kobo. Those are guaranteed to be the latest, high-quality, and legal.
I get the appeal of wanting a free PDF or EPUB floating around, especially with how slow official translations can feel. But those fan-translated sites are a mess—scattered across different aggregators, often with inconsistent quality, missing volumes, or weird formatting. The 'latest' volume might be a machine-translated mess from a raw source, which is borderline unreadable. If you absolutely need a free option, some public library systems have partnerships with services like OverDrive or Hoopla where you can borrow digital copies with a valid card. It’s a waitlist situation usually, but it’s legitimate and works on an e-reader app. The search for a quick download often leads to more frustration than it’s worth, in my experience.