Naveen has gone to investigate a Rogue Mega Ampharos and could use your help.
Go to the Ampharos
Go to Hibernal Pokémon Center in the northeast part of town, then go northwest from there to the mission destination. Approach Naveen at the Holovator. Then talk to Gwynn to start the battle. Gwynn of the Fist of Justice has a level 45 Banette, a level 46 Gourgeist, a level 46 Gengar, and a level 47 Chandelure that she Mega Evolves.
Afterward, Gwynn will heal up your Pokémon.
Go up the Holovator and go toward the mission destination. Go across the scaffolding on the part of the roof that is lower. Keep following the path along the rooftops. Eventually you find the TM for Toxic Spikes. You can drop down to the lower roof, where there is a ladder up to the roof that the Ampharos is on. Climb up that ladder and approach Ampharos.
Battle the Mega Ampharos
The Mega Ampharos will sometimes send rings of energy at you. Keep moving while it does this attack, since each ring will aim at you as you move. Sometimes it will run to the middle and do an electric attack surrounding itself, so be sure to keep your distance when it runs to the middle. It will also create electrified spots on the ground, so be sure to avoid running into these.
At other times, it will charge up an attack, which will create lightning bolts. Keep moving to avoid getting hit by a lightning bolt. After this, there will be small spots of electricity that move across the ground, so avoid getting in the path of these.
When the Mega Ampharos's health is about 50%, its attacks will get stronger, with more lightning bolts, and more spots of electricity that move around for a longer time.
Afterward, you get Ampharosite.
Moving On
If you haven't done the other two Main Missions, you can do them now.
After You Complete All Three
After you complete all three missions, Continue with Main Mission 20: A Request from the Rust Syndicate.
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