I'm surprised why people haven't been using toxic on Cresselia, as that's a great way to counter it, as well as any other cm poke. Anyway, if you start to have problems with status on Cress, I would suggest switching Moonlight to Rest, especially since Moonlight heals less in Sandstorm in Rain, which are both common. However, if you don't like Rest, a kind of random move I use is Magic Coat. It actually works somewhat well, as this catches people off-guard, as well as blocks taunt, but it is risky as you no longer have any means of recovering. I just use it for fun lol.