"Pokemon Sun and Moon" is not an easy game to play as simply grinding through countless encounters won't instantly make a Pokemon reach elite status. However, there are certain NPCs, such as the "Move Reminder" and "Move Deleter" that could make a players' life a little easier and here's how they can be found.
According to The Bitbag, the "Move Reminder," formerly known as the "Move Relearner," is an NPC that allows players to make a Pokemon relearn a move it once had. Players will be able to find this NPC the first time they go to Ula'ula Island.
The "Move Reminder" can be found beside the Pokemon Center and is just beside the Poke Mart. So to get this NPC, players just needs to reach the Pokemon Center at the top of Mount Lanakila.
Of course, the NPC doesn't come for free, as players will need to give one Heart Scale per transaction. Fortunately, there's an easy way to get a Heart Scale, as players just need to order the Special Z-Set at the restaurant in Konikoni City at Akala Island. The set costs 1,040 and the restaurant owner will give the player two Heart Scales every time.
Aside from the "Move Reminder," there's also the "Move Deleter," which allows players to delete a move of their Pokemon that they no longer need to make space for another move. According to RPG Site, the "Move Deleter" is a bald old man that is found inside Hau'oli City's Pokemon Center.
More NPCs that can help the players in "Pokemon Sun and Moon" are the "Frenzy Plant," "Blast Burn," and "Hydro Canon." These moves are exclusive to starter Pokemon from any of the regions. But they can only be taught if the Pokemon is already in its evolutionary stage.
The tutor can be found in Hau'oli City Shopping Mall. Another helpful NPC is the "Volt Tackle," an electric-type move that is great for Pokemon like Pikachu. This can be found in Konikoni City, just look for a girl standing by three Pikachu.
Other helpful NPCs are the "Relic Song" for Keldeo and the "Secret Sword" for Meloetta. These NPCs can be found at the Hano Grand Resort Hotel. Just look for a grey-haired guy wearing a blue patterned shirt.
Two of the most powerful moves that NPCs can teach are the "Draco Meteor," for dragon-type Pokemon, and the "Draco Ascent," a move unique for Rayquaza. These NPCs can be found in the Seafolk Village Pokemon Center.
A girl will teach the "Draco Meteor" and she can be found near the food store. An older balding guy will be the one to teach the "Draco Ascent."