http://www.smogon.com/dp/pokemon/cresselia
I decided to post this after seeing a thread in Stark where a team using this has gone undefeated. I tested it quite a bit and it is very good, very similiar to Uxie but Lunar Dance is what warrants its own set. And better defenses.
[SET]
name: Dual Screen
move 1: Reflect
move 2: Light Screen
move 3: Lunar Dance
move 4: Thunder Wave / Ice Beam / Psychic
item: Light Clay
nature: Bold
evs: 252 HP / 60 Def / 44 SpD / 152 Spe
[SET COMMENTS]
<p>Cresselia is really lacking in the attacking department, and is set up fodder for many Pokemon. This set turns the tables by setting up on your opponent. Cresselia possesses the greatest dual defenses of any Psychic-type outside of Lugia, allowing her to utilize dual screen effectively.</p>
<p>The strategy with Cresselia is mostly the same as it has always been; come in on a foe that can't do much damage to you and set up on the switch in. However, Cresselia can use Thunder Wave to great success. If you can hit your counter with it, then it'll be slower than you, pretty much guaranteeing you'll get up both screens seeing as how no unboosted attack can OHKO Cresselia when she is behind the appropriate screen. Ice Beam is another option over Thunder Wave because it hits one of the most popular Taunt users, Gliscor, for super effective damage and if Cresselia does get Taunted, it won't be a sitting duck. Psychic is another attacking option for Cressalia and makes it one of the best counters to Infernape and Lucario, but even with STAB, don't expect it to do a lot of damage. Unlike any other Pokemon, Cressalia learns the move Lunar Dance, which is her signature move. Once you are done setting up, she can sacrifice herself to bring in a Pokemon fully healed Pokemon. Lucario is a good choice for this, because he resists the attacks that Cressalia fears: Dark, Bug, and Ghost. This gives you two chances to sweep your opponent, hopefully when its counter has been knocked out or significantly weakened.</p>
<p>The EVs are rather specific: Choice Band Tyranitar nor Choice Specs Gengar can 2HKO you while you are behind a Reflect or Light Screen, respectively. 152 EVs in Speed lets you outpace Jolly Tyranitar and Adamant Scizor, but maxing Speed may be helpful to outspeed Heracross and the like. Light Clay is the preferred option so your dual screens remain for the full 8 turns.</p>
I decided to post this after seeing a thread in Stark where a team using this has gone undefeated. I tested it quite a bit and it is very good, very similiar to Uxie but Lunar Dance is what warrants its own set. And better defenses.
[SET]
name: Dual Screen
move 1: Reflect
move 2: Light Screen
move 3: Lunar Dance
move 4: Thunder Wave / Ice Beam / Psychic
item: Light Clay
nature: Bold
evs: 252 HP / 60 Def / 44 SpD / 152 Spe
[SET COMMENTS]
<p>Cresselia is really lacking in the attacking department, and is set up fodder for many Pokemon. This set turns the tables by setting up on your opponent. Cresselia possesses the greatest dual defenses of any Psychic-type outside of Lugia, allowing her to utilize dual screen effectively.</p>
<p>The strategy with Cresselia is mostly the same as it has always been; come in on a foe that can't do much damage to you and set up on the switch in. However, Cresselia can use Thunder Wave to great success. If you can hit your counter with it, then it'll be slower than you, pretty much guaranteeing you'll get up both screens seeing as how no unboosted attack can OHKO Cresselia when she is behind the appropriate screen. Ice Beam is another option over Thunder Wave because it hits one of the most popular Taunt users, Gliscor, for super effective damage and if Cresselia does get Taunted, it won't be a sitting duck. Psychic is another attacking option for Cressalia and makes it one of the best counters to Infernape and Lucario, but even with STAB, don't expect it to do a lot of damage. Unlike any other Pokemon, Cressalia learns the move Lunar Dance, which is her signature move. Once you are done setting up, she can sacrifice herself to bring in a Pokemon fully healed Pokemon. Lucario is a good choice for this, because he resists the attacks that Cressalia fears: Dark, Bug, and Ghost. This gives you two chances to sweep your opponent, hopefully when its counter has been knocked out or significantly weakened.</p>
<p>The EVs are rather specific: Choice Band Tyranitar nor Choice Specs Gengar can 2HKO you while you are behind a Reflect or Light Screen, respectively. 152 EVs in Speed lets you outpace Jolly Tyranitar and Adamant Scizor, but maxing Speed may be helpful to outspeed Heracross and the like. Light Clay is the preferred option so your dual screens remain for the full 8 turns.</p>