I believe I made the exact same build with a Staryu when I was dared to create a team with only basic evolving Pokemon. It worked for a bit, but then it got hit by Toxic so it totally fell over. I replaced Recover with Rest just because of that, and it just as easily fell, especially since after setting up Cosmic Powers, I got Roared away by a dang Poochyena which survived a STAB Surf. (It got rid of the Sleep... hahaha.) Though it worked on your first battle, don't be so sure that it'll work all the time. You probably lucked out if your opponent didn't have a T-Wave Blissey with Seismic Toss or Toxic/Curse Dusknoir with Shadow Sneak. You would probably want to switch to get rid of status changes, but that defeats the purpose of buffing.