Lately I've been thinking of how common Thunder is in Ubers, when I realized that there really are no STAB users of the move. I came up with this Raikou set that I think has potential.
Hasty; 40 Atk / 216 SpA / 252 Spe
With its decent base 90 attack and access to a powerful physical dark attack, Raikou is able to inflict damage on the Psychic-filled Uber metagame, which features pokemon that tend to be weaker when it comes to physical defense. This Raikou is intended to lure out Latios and Latias while also serving as a naturally speedy revenge killer to slower threats such as SDGarchomp, non-scarf Kyogre, and possibly Ho-Oh. The EVs generate enough Attack to 2HKO Latias with Stealth Rock, 352 Speed to outpace Max Speed Timid Latios by 2 points, and maximum SpA for the most possible power.
Crunch is one of the most important moves on the set. With a Hasty nature, some Attack investment, and Life Orb, it manages 44.98% - 53.50% to a 112 / 0 Neutral Latias, a guaranteed 2HKO with Stealth Rock. The same is true of the defensively weaker Latios. Because Raikou outspeeds them both, it can Calm Mind on the switch and proceed to 2HKO with Crunch, while 252 Timid Latios can only manage a maximum 84% with Draco Meteor to +1 Raikou, which never OHKOs with Stealth Rock. Ideally, though, Latios would be caught on the switch with Crunch for a quick 2HKO.
Calm Mind is self-explanatory - it allows Raikou added offensive firepower while softening blows from the many special attacks in Ubers, such as Latios' Draco Meteor. In fact, Scarf Palkia's Spacial Rend can only manage 37.96% - 44.86%, making revenge killing somewhat difficult if Raikou is in good health. At +1, Raikou's Thunder OHKOs Lugia, Kyogre, Palkia, Physically Defensive Mewtwo, 248 / 248 Careful Ho-Oh, and others.
Thunder provides Raikou with a powerful STAB attack, fully accurate in the Rain. Despite Raikou's already high base speed, it can also spread around paralysis should a faster scarfer attempt to immediately switch in.
Hidden Power Ice is necessary to round out the coverage of the set, pairing well with Thunder and also Crunch due to the presence of dragons in the Uber metagame. It has an 50.03% chance to 2HKO 252 / 60 Adamant support Groudon, after accounting for Stealth Rock and Leftovers, often the most specially defensive of Groudon encountered. At +1, 86 / 96 neutral Giratina-O is 2HKOd, though ResTalk versions are difficult for Raikou to deal with. Moreover, it allows Raikou to OHKO non-Yache Garchomp, as well as Rayquaza, both of which it outspeeds. These are important as Garchomp could otherwise KO with Earthquake, while Rayquaza's Air Lock makes Thunder inaccurate despite the rain.
Despite the positives of the set, Raikou has trouble with Giratina(-o), Blissey, Dialga, and faster scarfers. It works well with Kyogre because it can lure in and kill the Lati twins, while Kyogre can plow through all else if equipped with Specs. ScarfDialga is also a good choice, as it resists SDRay's Extremespeed attempts at revenging Raikou, and can also overcome Giratina and other Dialga with Aura Sphere, as well defeating faster threats such as Darkrai or Shaymin-S.
As far as support is concerned, it is important to use a lead that can set up Stealth Rock as well, to ascertain particular KOs such as Latias. Furthermore, it is generally a good idea to have Kyogre somewhere on your team to retain control of the weather - rain is necessary to keep Thunder accurate after all.