I would only run Raikou in the Expanded format as there is a very relevant way to abuse it, but it may not be as great against the really competitive metagame.
4 Raikou
2 Eelektross (Primal Clash)
4 Eelektrik (Noble Victories)
4 Tynamo
2 Shaymin-EX
1 Keldeo-EX
1 Mr. Mime
3 Rough Seas
3 Muscle Band
2 Float Stone
10 Lightning Energy
4 Professor Sycamore
3 AZ
3 Lysandre
4 Ultra Ball
4 Traniers' Mail
3 VS Seeker
3 Acro Bike
1 Super Rod
I know this isn't the best list, but at least you can get a feel for what the concept is overall. Basically, you want to get it down and active turn 1. Then slowly get Eelektriks out on turn 2. At this point, you also should attempt to draw into Keldeo-EX (or Ultra Ball) and Float Stone. Have a Raikou on the bench receive Eelektrik energy discarded by Ultra Ball, Acro Bike, and Professor Sycamore, Rush In and retreat, then get the first attack. Next turn use another Dynamotor if possible and then evolve into Eelektross, but just one of them. It will allow you to move all of your basic Energy to the active Pokémon hence why there is no Flash Energy in this list. During the game, if you need to heal, and Rough Seas isn't covering it, Rush In with Keldeo-EX, retreat to another Raikou, use Eelektross to move the energy to the active, AZ your Raikou, and then play it back down like nothing ever happened. Pretty cool, right? Hope this helps!
-shifty14326 on YouTube