> The user faints but the next Pokémon released is fully healed.
> The user faints and the next Pokémon released is fully healed.
Lunar Dance is exactly the same as Healing Wish, only it has a better name. Healing Wish is a fantastic late-game support move. Use it when you need to bring back that 13% HP Terrakion to win the game. Healing Wish is a common move on Mega Lopunny, Mega Latias and Jirachi t ouse when they have outlived their usefulness.
So to answer your question, yes Lunar Dance is viable on support Cress. However, you seem to be running an offensive Cresselia. That's not her best playstyle, but whatever floats your boat. Lunar Dance is still useable, but Ice Beam would probably be a better fit. Here is a moveset for Support Cress:
EVs: 252 HP / 112 Def / 148 SDef
- Lunar Dance