If you saw the video, that was kind of outdated. I only use Latias in most of my teams. I follow tiers instead of banning legendary Pokemon regardless of how they play. Like, Entei is banned in some tournaments because it is a legendary, but it really is sucks entirely for having a extremely bad movepool, and having Fire Fang as his strongest physical Fire attack lol. Plus, it is SR weak.
Edit: Oh, retrain...