User blog:RedYoshiNation/HOW TO GET ANY LEGENDARY YOU WANT ON USUM (NO HACKS)

Step 1. Find an Ultra Beast Step 2. Catch it dont kill it Step 3. Go to GTS and despoit that ultra beast and type in the legendary you want! If you want one from Ultra Sun only then you will have to despoit a ultra beast from Ultra Moon only and If you want one from Ultra Moon only then you will have to despoit a ultra beast from Ultra Sun only Step 4. Wait for a few hours

It worked for me I despoited a Cresteela and said I wanted a Groudon and I got in 1 day! :D