You can buy TM25 Thunder from the Technical Machine Shop located in the Seafolk Village Pokémon Center. The following TMs can also be bought from this shop: TM04, TM14, TM22, TM34, TM38, TM52, TM68 and TM71.
Seafolk Village is located on Poni Island. You will gain access to Seafolk Village once you complete the following events in the main story:
- Clear the Ula’ula Island grand trial
- Rescue Lillie from Aether Paradise
Obtaining TM25 (Step-by-Step)
During your playthrough you will first arrive at Seafolk Village from the pier on the southeast.
Step 1: Walk a short distance west until you leave the pier.
Step 2: After leaving the pier, keep walking north until you reach the central platform.
Step 3: On the central platform, take the path to the left.
Step 4: Continue on the left-side path and walk north, past the first pier.
Step 5: Keep walking north, then turn left once you reach the second pier.
Step 6: Enter the Pokémon Center once you see it.
Step 7: Inside the Pokémon Center, walk to the counter on the right side.
Step 8: Talk to the clerk on the right side of the counter and select “Buy”.
Step 9: Select Thunder, which is the fifth item in the TM Shop’s menu.
Step 10: Choose “Yes” to buy TM25 for 30,000 PokéDollars.
Thunder Details + Use
|Thunder Move Details
Thunder is a damage-dealing move. As a secondary effect it also has a 10% chance of inflicting Paralysis on the target.
Despite being a very powerful move, Thunder has accuracy as a downside. With only a 70% chance of hitting the target, Thunder can be unreliable. However, the 110 base power often can make up for the misses.
Under rain, Thunder bypasses all accuracy checks. For this reason, Thunder is the staple Electric type move for Rain Dance-based teams.
On the other hand, Thunder’s accuracy drops to 50% under harsh sunlight. Keep an eye out for Sunny Day-based teams.
In competitive play, Thunder can also be used outside of Rain Dance teams. Thunder is an option as a STAB move for Electric types, and also as a coverage move. However, because of its low accuracy, Thunder is often replaced by Discharge or even Thunderbolt. Therefore, you will rarely see Thunder being used outside of rain teams.
But Thunder isn’t a very good option for the main story playthrough. Most Electric-types learn Discharge by leveling up. You will also gain access to the Thunderbolt TM around the time Thunder becomes available.
Both Discharge and Thunderbolt are better alternatives as Electric type moves for a main story playthrough.