While torrenting technology itself is legal for sharing open-source files, using it to download copyrighted TV shows like American Ninja Warrior without permission is illegal in the U.S. and many other countries.
You can find the latest seasons and various past episodes through these authorized providers: American Ninja Warrior Download Torrent
If you want to own the episodes forever without a subscription, you can buy individual episodes or full seasons on: Apple TV / iTunes Google Play Movies Why Support the Show? While torrenting technology itself is legal for sharing
: Entire seasons can be downloaded at once, providing a comprehensive viewing experience without the need to download each episode individually. : Entire seasons can be downloaded at once,
: You can stream the most recent episodes for free with ads or log in with your TV provider to access the full library.