As you start heading into Lumiose City again, Shauna will catch up with you and speak with you. She’ll direct you to Prism Tower , so take one of the two paths leading toward it. You’ll be in a new area. Continue on through to Prism Tower.
Once you arrive there you’ll be able to watch Prism Tower’s lights activate. It’s novel. From there it’ll be revealed that Prism Tower itself is the gym. Whenever you’re ready to, head on in and take the gym on.
It’s an Electric-type gym if you haven’t already guessed. Check the above table for recommended Pokémon types to bring or avoid. Ideally, you should have a Ground-type or two - not only do these Pokemon do double damage, but they’re immune to Electric moves! Once you’re all ready head up the elevator.
On the next level it’ll be revealed that you need to correctly answer quiz questions to progress through this gym. That or you can purposely fail and battle extra trainers. Your choice really. Either way, step up to the counter and the quiz will begin.
First you’ll be asked which Pokémon the shown silhouette corresponded to. It was Pikachu (if you didn’t know this, shame on you!), so door three. Head there if you want; if not you can take the other two trainers on too. They are as follows:
Once you answer it correctly you’ll proceed to the next floor. Here you’ll be given another silhouette that you’ll need to guess the identity of. This time it’s Fletchling , a Pokemon you should have met very early on, so door one. Feel free to take on the other two trainers beforehand if you want. The trainer list for this floor is as follows:
Once you choose the correct answer you’ll head to the next floor. The next silhouette is tricky because there are three very similar Pokemon, but the correct answer is Panpour , so door three again. You know the drill.
Once you choose the correct answer you’ll again head to the next floor. This quiz works a little differently. It’s asking which silhouette is Vivillon’s . It’s the second one, so door two it is. The info for the three trainers here is as follows:
Once you get it right and head to the next floor, you’ll have reached the Gym Leader. Wow! Time to take him on. Good luck and such! Feel free to head back to the Pokemon Center and heal first too. Once you’re good to go, go.
Heliolisks Dry Skin negates Water damage, so definitely no Water-types here.
For Emolga, don’t use pure Ground-types as it’s part Flying-type and thus immune to Ground moves! If your Ground Pokemon has other moves, like Rock-type moves, then ace. Magneton takes quadrule damage from Ground moves, so should be easy to floor. Finally, feel free to smack Heliosk with Fighting-type moves.
Once Clemont’s taken care of you’ll be given the Voltage Badge. This means that any Pokémon up to Level 70 that you received in a trade will obey. How swell. He’ll also hand you TM24 - Thunderbolt. Nice. That’s all then!
Head to the elevator and take it to the first floor. Head on outside. We have some serious exploring to do. As you get outside you’ll receive a Holo Clip from Sycamore. He’ll ask you to meet him at Lysandre Cafe. Let’s do that as we’re exploring the city!