Now that they are together you will just have to wait and see. Usually it is best to ask this type of question before you put the fish in the tank.
Dogfaced puffers are mean SOBs. They will try to eat everything and anything, and can get to be as large as basketballs when fully grown and all puffed out. The damsels and butterfly are lunch, and possibly the grouper as well if it doesn't keep well hidden and out of the puffer's way. I don't know if the puffer will mess with the lionfish, given the lion's venom, but it may just be aggressive enough to out-compete the lion for food as well as stress the lion out with his active swimming and harassment.
Plan on making the grouper into a nice sandwich in the future. These fish are ones that I strenuously object to being in captivity. The junvinals are beautiful, very brightly colored, but as they grow older (and subsequently larger) their colors dull and many species grow quite large (think of its relative the Nassau Grouper, or the Jewfish!). They will attempt to make lunch of anything that fits into their large mouths (hense the name grouper) although they can be weaned onto most frozen foods.
Lionfish really ought to be in a lionfish only tank unless they are very large. Another beautiful fish, be wary of the spines along their back, they are poisonous, and can give you a nasty anaphalixis reaction if you get stung. Keep small children away from a tank of lions, since we all know a child near a fishtank is eventually a child in the fish tank. They can be a difficult feed, and although they will attempt to eat large food items, this isn't a good idea for they are known to choak on things bigger than themselves. Another live fish eater, they are slow hunters, preferring an ambush type of attack. Your grouper and puffer may be too active for the lion, and shy it, or beat it to the food.
Butterfly fish are known as the most picky eaters and most difficult fish to keep in the hobby. They need small, fine live foods, such as artiema or copopods, and like to pick that food out of crevices and holes, although most may eat prepared foods if weaned to them. They are especially sensitive to water quality, and if you are feeding live food to predators, this can cause major maintance issues while trying to keep the tank clean enough for a butterfly. The puffer will probably make him lunch.
Good luck.
~~Colesea
