As you continue to earn and play the Roto Loto on your Rotom Pokedex, you will receive what are called Rotom Powers. These powers are very similar to that of O-Powers from previous Pokemon Games, each aiding your trainer in a certain area during your second journey through The Alola Region. There are a total of eleven different Rotom Powers you can earn.
Rotom Powers
Roto Bargain (Rare): Reduces PokeMart Item Prices By Half
Roto Boost (Rare): Raises All Stats On Your Battling Pokemon
Roto Catch (Rare): Increases The Chances of Catching A Wild Pokemon
Roto Encounter (Uncommon): Increases The Chances of Finding High-Leveled Wild Pokemon
Roto Exp. Points (Rare): Increases The Exp. Points Your Pokemon Earn In Battle
Roto Friendship (Uncommon): Increases A Pokemon's Friendliness
Roto HP Restore (Rare): Fully Restores A Pokemon's HP
Roto Hatch (Uncommon): Helps Eggs Hatch Faster
Roto PP Restore (Common): Fully Restores The PP On A Pokemon's Moves
Roto Prize Money (Uncommon): Triples Prize Money Earned From Battles
Roto Stealth (Common): Prevents Wild Pokemon Encounters
As you continue to bond with your Rotom Pokedex, you could eventually unlock its special Z-Rotom Power. With this special power, when you've reached maximum affection with Rotom, you can call on your Rotom Pokedex by using a Rotom Power during battle or having a Rotom Power in play outside of battle, to come to within a battle to provide you with a boost to your Z-Power. This will then allow you to use Z-Moves for a second time during a battle.