Brave Vesperia, it's not "bad", it's just it really gained nothing while rain and sun gained a lot. I wouldn't say you lose every game, more like it's very difficult to play against other weathers (sun might be a little in your favor though).
If you really want to run it, Regenerator Amoonguss is pretty much a must. A few sand abusers such as normal Landorus (don't run the new forme in sand), Terrakion, CB Stoutland, or even Sandslash are needed. A few defensive pivots such as Jirachi and Gliscor help check some of the new threats. Balloon Heatran helps vs sun.