Thunder
Thunder is Raikou's most powerful move which it can achieve at Level 85 by gaining experience points in battle. Thunder is an electric-type move which strikes the enemy with lightning, causing them to lose Hit Points and standing a 30 percent chance of paralyzing them for a turn so they would miss one turn of the battle and have no chance to attack. Thunder has 10 Power Points, meaning that Raikou can only use it 10 times before recharging at a Pokemon Center. The move's accuracy rate of 70 percent is relatively low, but is worthwhile for its power rating of 120, meaning it can inflict a lot of damage. Because Raikou is also electric-type, the damage is increased by 50 percent, making this a formidable attack.
Rain Dance
Rain Dance is a status move -- it doesn't take any HP from the enemy, but affects them in other ways. This is a water-type move which makes it rain on the battlefield for five turns. During this time, the accuracy of the Thunder move is improved 100 percent, meaning it hits every time, and fire-type enemies have the power of their attacks cut by 50 percent. Raikou can learn this move at Level 71, but can only use it five times before recharging. Try using it followed by Thunder to deal massive damage to enemies.
Hyper Beam
Raikou does not learn Hyper Beam naturally by leveling up, but can learn it by using a Technical Machine which teaches special moves to Pokemon. Hyper Beam is TM number 15 in all Pokemon games. This move fires a powerful laser beam at the enemy, inflicting large amounts of damage -- it has a power rating of 150 and an accuracy of 90 percent. However, if the attack is successful, Raikou must rest for the next turn and take no action, so it's best to use Hyper Beam to finish off enemies who are running low on HP. It can only be used five times before recharging.
Crunch
Crunch is always a handy move to keep around, as it is a "dark" type move that can affect many Pokemon which may be impervious to Raikou's electric-type attacks. Crunch is learned at Level 43, and is essentially a powerful bite -- a pair of jaws clamp down on the enemy, causing them damage. It also has a 20 percent chance of lowering the enemy's defense stat, which leaves them weaker to subsequent attacks. Crunch has 100 percent accuracy, and combined with its power rating of 80 and 15 PP, it is a good move to have available when others are running low on PP.
Thunderbolt
Thunderbolt is another useful option for Raikou to have, and can be learned from a TM. Thunderbolt is always TM number 24. Thunderbolt does exactly what it sounds like -- it strikes the enemy with lightning, causing them to lose HP. It's similar to Thunder, except slightly weaker with a power rating of 95. However, it has a 100 percent accuracy rate and 15 PP compared to Thunder's 10, so it can be good for taking care of large numbers of weaker enemies. It is an electric-type move, which means it gains a 50 percent damage bonus due to Raikou also being electric-type.
Calm Mind
If you're not using Thunder, there's not a lot of point in having Rain Dance, so a good alternative status move is Calm Mind. This move does not affect the enemy in any way, but raises Raikou's Special Attack and Special Defence stats, increasing the strength of your electric attacks and weakening the enemy's special attacks. Following this with Thunderbolt or Hyper Beam deals massive damage to the enemy. Raikou can learn Calm Mind at Level 81, and can use it 20 times before recharging.