Suicune stands strong with its unparalleled mixed bulk, especially in comparison to other bulky Water-types. Its access to Calm Mind and good STAB can make Suicune a strong offensive threat as well. Suicune also benefits from the presence of rain, as its typing allows it to take on many common threats in rain while it enjoys the boost rain grants to its own STAB move.
Unfortunately for Suicune, a lot has changed in the new metagame, and it struggles to make a name for itself as a result. BW2 has ushered in a more fast-paced and highly offensive metagame, which means Suicune's bulk sometimes isn't enough to withstand even unboosted hits. The ever-present nuisances of Ferrothorn and Celebi make it hard for Suicune as well. Finally, Suicune receives stiff competition from the likes of other Pokemon such as Keldeo and Latias as a Calm Mind user in OU. Regardless, Suicune may have taken a hit in its effectiveness, but it still stands strong as a bulky Water-type that can potentially hit hard.
A relic from the ADV era, CroCune stands as Suicune's only viable set in the BW2 OU metagame. Using its high defenses, good typing, and Calm Mind, Suicune can make for a solid and bulky late-game sweeper. While the sleep mechanics of the fifth generation have somewhat hindered this set's effectiveness, Suicune's unparalleled bulk allows it to survive the turns of Rest, especially when its counters have been removed from the match. Pressure is also a great asset, allowing Suicune to stall the PP of moves such as Thunder and Giga Drain. Boosting Suicune's special stats to formidable levels with Calm Mind is this set's ultimate goal. Scald is a solid STAB move that hits fairly hard after multiple boosts; the burn chance also complements Suicune's ability to take hits. Rest is unfortunately Suicune's only form of recovery, although Suicune has enough bulk to endure the sleep turns. Sleep Talk is in the final moveslot so that Suicune can accomplish either gaining extra boosts or firing off Scalds while it's asleep.Team Options & Additional Comments >>>
Although Suicune has a shallow movepool, it does have some other options it could use. Suicune is perfectly capable of using its access to Calm Mind to take a more offensive approach, but it is generally outclassed by Keldeo in this regard. Ice Beam is a solid coverage move that can handle Grass- and Dragon-types well. Roar is a good move to shuffle the opposing team on more defensive sets. Hidden Power Grass or Electric is perfectly usable if opposing Water-types pose a significant threat to the team. Toxic is also usable to wear down defensive Pokemon. Tailwind is an interesting option for a temporary speed boost to help Suicune and its teammates. Finally, Rain Dance is viable for Suicune to support Swift Swim sweepers.
Checks and Counters
Grass-types, particularly Abomasnow, Celebi, and Ferrothorn, can endure multiple Scalds and hit Suicune hard with their STAB moves. However, the burn chance from Scald may neuter the threat of the latter. Latias and Latios can take on anything Suicune has to offer and either Trick or bypass Suicune's Special Defense boosts with Psyshock. Thundurus-T is a notable check to Suicune, as its powerful Thunderbolt is a death sentence without several Special Defense boosts. Although Suicune is reasonably bulky, its lack of recovery means powerful attacks such as Terrakion's Close Combat and Salamence's Outrage will take their toll on it. Bulky Water-types, particularly Gastrodon, Jellicent, and Vaporeon, don't mind anything Suicune does and can wear it down with Toxic. Kyurem-B can take Suicune on and reset its boosts with Dragon Tail, set up a Substitute on it or smash it with Fusion Bolt. Toxicroak takes nothing from Suicune and can use it as setup fodder. Finally, defensive Ninetales can weaken Suicune's Scald with the sun and Roar it out, resetting any boosts it had obtained.
Suicune gets Water Absorb from the Dream World. This ability will be more useful than Pressure, as it allows Suicune to come in on Water-types such as Keldeo and have some form of recovery aside from Rest. Pressure's PP stalling may be missed at times, but Water Absorb will be the superior ability the majority of the time.