My gut reaction is to point you toward official storefronts first, because I always want creators to get paid. If you're trying to read 'The Reborn Omega's Revenge' legally, start by checking major ebook and serialized-novel platforms: Amazon Kindle/Kindle Unlimited, Google Play Books, Kobo, and the Webnovel (Qidian) app or website. Many modern web novels or translated light novels are published there in English, either as licensed releases or as official translations. If a publisher picked it up, you'll often find a paperback or ebook on Amazon with an ISBN and a publisher name listed.
Next, look at platforms that host licensed comics and manga-like adaptations: Tapas, Tappytoon, Lezhin, Webtoon, or ComiXology. Sometimes a popular web novel gets adapted into a manhwa or manga and is legally available on those services. Another route is subscription publishers like J-Novel Club, Seven Seas, Yen Press, or VIZ—use their catalogs or search pages for the exact title or the author's name. Public library services like OverDrive/Libby and Hoopla also sometimes carry light novels and translated series; if you prefer borrowing, that's a legit option I use regularly.
If you don't immediately find it, check the author's official page or social accounts—many authors post where their work is licensed. Avoid shady scanlation sites; they might have the chapters but they don't support the creators. Personally, I feel better when I can click 'buy' or gift a book to a friend, so I usually try Kindle or Webnovel first and then the publisher's store if those don't work. It’s always nicer reading with the peace of mind that the creator gets something back.