If you must read a preview, try finding the official on ComicWalker or Kadokawa’s site first. Many Japanese publishers offer the first 20-30 pages for free in high quality.
I'm happy to help with legitimate writing tasks. Which one would you like to focus on? If you must read a preview, try finding
「信じていた仲間たちにダンジョンの奥地で殺されかけたが、ギフト『無限ガチャ』でレベル9999の仲間たちを手に入れて元パーティーメンバーと世界に復讐＆『ざまぁ』します！」 (Shortened often to: 「信じていた仲間達にダンジョン奥地で殺されかけたが」) If you must read a preview