Cresselia is a psychic type Pokémon, seems like it flies, but it just floats. Looks pretty prim and proper to me, it can be shiny, so the hunt is definitely on.

Download full size guide here

Cresselia Raid Guide
Find out how to take down this Peacock Pokemon.
Capt Goldfish

Is it useful? For PvE, nope. It’s just going to sit in your box, unless you flex your shiny while you let others win the raid for you. Pvp though, it’s pretty solid. It has an exclusive move in Grass Knot, you don’t need it, but you’re going to be mad you didn’t have it plenty of times. You’re going to have to trade to make it under the 1500cp for great league, but open ultra league is where it shines. It’s one of, if not the top non xl pokemon in open ultra, such a bulky bird.

The best counters are going to be your dark types, and the ghosts. A trusty old Tyranitar is probably sitting there feeling neglected, easy to build Gengars are ready to do tons of damage and use up your revives, hopefully you picked up some Darkrai this last raid cycle, and little Litwick are ready to lead the pack. You could do this with 3 trainers, but are you really that good and still reading this? You might want to get a few more so you don’t have to stress about your friend who just went in with recommended, and put his Murkrow buddy in there to earn a heart. Hey, it happens.

Go to the official counters page for a complete list, and see how your Pokemon perform.