My Lunatone knows Cosmic Power, and when I was on PKMN Showdown, it said Baton Pass was a possible move. But it doesn't say here that Lunatone can learn Baton Pass. One of my other Pokémon could really use those Cosmic Powers. Thanks in advance.
In XD, a shadow Lunatone can learn baton pass when it's purified. If you don't have a copy of XD then I guess you can't get a baton pass Lunatone.
Even if you could use cosmic power and baton pass, I would not encourage it because your opponent can easily mess up everything just by using roar. Using cosmic power also requires paying a power bill.