Being one of the best special sweepers in the game, Raikou is one of the Pokemon that forces people to use standards. It's fast, has a great STAB, and can set up on many Pokemon in OU.
This is the most common Raikou set and by far the most immediately dangerous one. After a Calm Mind, Raikou can severely dent almost anything switching in. Substitute is the usual option, allowing Raikou to set up in the face of special attackers that can't break its Substitute. It also blocks status and provides a buffer against critical hits. Roar is a decent option as well though, allowing Raikou to beat any opposing Calm Mind user, scout, and rack up Spikes damage on Raikou's most common counters: Blissey, Snorlax, and Celebi. Hidden Power Grass gives Raikou an edge against Swampert, while Hidden Power Ice deals with the less common Flygon and gives Raikou an attack that hits Celebi for good damage.
Maximum Speed investment gives Raikou the jump on Adamant Aerodactyl and lets Raikou at worst Speed tie other Raikou and Starmie. When using Roar, being able to Roar out opposing Raikou first can be devastating. Maximized Special Attack increases Raikou's power.Team Options & Additional Comments >>>
Rest grants Raikou recovery and allows it to take hits much more comfortably. The goal of this set is for Raikou to set up Calm Minds in the face of any special attacker and then Rest to repeat the process. This Raikou works much like a special version of Snorlax in that it can take hits and dish out damage right back.
With RestTalk, Raikou no longer has to worry about switching into Milotic's Hypnosis, becomes quite possibly the best Gengar counter in the game, and can even stall out Blissey with Pressure; however, it is unable to touch Dugtrio and other Ground-types. Consider Porygon2 as a partner and play cautiously. This Raikou acts as a superb special wall and attacker, but it is not able to force itself through Ground-types without assistance.
This set should run 300 Speed for neutral base 100 Speed Pokemon. 252 HP EVs grant maximum bulk; the rest is put in Special Attack for a bit more punch.
Although similar to the last set, this one doesn't bother setting up Calm Minds, as the threat of Dugtrio and other Ground-types continues to increase. Instead, it plays the role of a pure special wall, absorbing sleep while countering the most common special attackers in the tier. Roar takes advantage of Spikes and can force out common answers to Raikou. Even better, if Raikou is asleep, Roar chosen by Sleep Talk will hit with normal priority, allowing most threats to be phazed out before they can even hit Raikou. If the threat of Ground-types is still too great to ignore, you can choose to run a Hidden Power, such as Grass or Ice, to keep them at bay.
The EVs are the same as the previous set, but this set plays fairly differently. Rather than setting up alongside special sweepers and being able to sweep by itself, this Raikou acts as a quick check to most special attackers, able to force the foe out and keep healing itself as needed. If you decide to use Hidden Power Ice, consider running 330 Speed on Raikou in order to check Flygon more efficiently.
Protect works well alongside Pressure to quickly stall out Blissey's PP. Thunder Wave is viable because paralysis is always nice, but it isn't the best choice for Raikou. With Psych Up, Raikou can copy Calm Mind boosts from Suicune. Crunch can be used over Hidden Power for better all-around neutral coverage and to hit Celebi a little harder, but this usually just renders Raikou unable to KO both Swampert and Flygon.
Checks and Counters
Dugtrio has difficulties switching in, but it can trap and OHKO Raikou. Furthermore, with 44 Special Defense EVs (48 with Hidden Power Bug), Dugtrio can survive a super effective Hidden Power from Timid Raikou. Adamant Dugtrio can therefore switch into Thunderbolt and not be KOed next turn, while Jolly Dugtrio can safely switch into any of Timid Raikou's attacks and proceed to OHKO with Earthquake. Of course, if there are Spikes on Dugtrio's side of the field, it will have a bit more trouble.
Blissey and Snorlax can take repeated hits from Raikou and KO it with ease. With Psych Up or Seismic Toss, Regice beats Raikou that lack Rest one-on-one by virtue of its high Special Defense. If it lacks those two moves, however, Raikou can set up with Calm Mind to the point where its Substitutes are unbreakable. Celebi with Perish Song can easily force out Raikou and can set up Calm Mind alongside Raikou while taking very little from Raikou's common attacks. Venusaur that pack physical moves, such as Sludge Bomb, can beat Hidden Power Grass variants, as can Flygon. Swampert is OHKOed by +1 Hidden Power Grass and 2HKOed otherwise, but it can switch into Thunderbolt and OHKO Raikou with Earthquake, as well as easily beat the less common Hidden Power Ice variants. Steelix and Camerupt are immune to Thunderbolt and take neutral damage from both Hidden Power Ice and Grass and can hit Raikou back with STAB Earthquake. Claydol also packs an Electric immunity and a high Special Defense stat, but it's 2HKOed by +1 Timid Raikou.
Although Marowak is 2HKOed by Hidden Power Ice or Grass, it can come in on Substitute and KO Raikou with Bonemerang. Similarly to Dugtrio, Marowak can be EVed to always survive +1 Raikou's Hidden Power (156/0 for Timid and 252/12 for Modest). While it is not the best counter, Marowak is a very important threat to be wary of; do not assume your Raikou is safe behind a Substitute or that your set-up Raikou can OHKO it. Finally, Jolteon matches up well against Raikou if it packs Roar or Thunder Wave.