Team Flare's true plans have been laid bare: They want to obliterate anyone who's not wearing their stylish suit. A terrible thing indeed... and you need to do something about it. Prep your team for a fight - you probably know what to expect from the members of Team Flare by now - then head off to Geosenge Town, on the far-west end of Kalos. It looks... a bit different.

Upon arrival you'll discover that the south end of Geosenge Town is blocked by Team Flare Grunts, barring your passage. The same goes for most of the buildings here. Head northwest out of Geosenge Town and you'll run into the first of a number of battles with the baddies.

Team Flare Grunt
  • Manectric, level 45
  • Scrafty, level 45
  • Golbat, level 45
Reward: 1,800 P

Continue northwest to the big stone formation on the outskirts of town. The first time you visited Geosenge Town you probably suspected that there was something back here, and, surprise surprise, there's an elevator. Hop on board.

Team Flare Secret HQ

You'll emerge belowground. No one in the first, big control room will fight you. Run to the north end and you'll find Lysandre, the now-official big bad of the game. Time for a rematch.

Team Flare Lysandre
  • Mienshao, level 47
  • Honchkrow, level 47
  • Pyroar, level 49
  • Gyarados, level 51
Reward: 10, 200 P

Lysandre hasn't changed much since the battle in Lysandre Labs, despite this being a climactic battle. Mienshao sports the greatest change, as its Hi-Jump Kick is substantially stronger, though the Pokémon on the whole is still quite frail. Honchkrow is a great deal more durable than before, but it's still not that strong. The other two are a teensy bit tougher. In other words, if you could beat Lysandre before, you can beat him now.

Lysandre is not deterred from his plans after he's defeated, and suggests you have a look at the legendary Pokémon for yourself. Go through the door to the left of Lysandre. On the way down you'll be faced by some more trainers, and your neighbor will jump in to help. You'll fight three battles together with them as you descend through the HQ.

Team Flare Admin and Team Flare Grunt
  • Toxicroak, level 50
  • Liepard, level 48
Reward: 7,840 P

Team Flare Admin and Team Flare Grunt
  • Mightyena, level 48
  • Manectric, level 50
Reward: 7,840 P

Team Flare Admin and Team Flare Grunt
  • Houndoom, level 50
  • Scrafty, level 48
Reward: 7,840 P

Keep running until you reach the bottom. After a cut scene... and a big, mysterious egg... you'll hit more Team Flare. Will it ever end? You're about to face four different Admins, so prepare for a bit of a slog. None of them are throwing curveballs with their teams. Your neighbor is no longer helping you, so be prepared for solo battles.
Team Flare Admin
  • Liepard, level 47
  • Manectric, level 48
Reward: 3,840 P

Team Flare Admin
  • Swalot, level 50
Reward: 4,000 P

Team Flare Admin

  • Mightyena, level 47
  • Houndoom, level 48
Reward: 3,840 P

Team Flare Admin
  • Golbat, level 50
Reward: $4,000 P

Approach the egg after disposing of the Admins. Thus comes the moment of truth . . .

. . . and your opportunity to catch your game's title legendary Pokémon! If you're playing Pokémon X, this will be Xerneas. If you're playing Pokémon Y, you're instead facing Yveltal. Both are fairly brutal legendary Pokémon which, if you're sane, you'll want to try to catch. The easy way to do this is to simply toss the Master Ball you received from the Poké Ball Factory - assuming you still have it - and call it a day. If you want to save the Master Ball for a more difficult legendary later on you'll have to drain Xerneas / Yveltal to a very low amount of HP using weaker moves, then start throwing Poké Balls. Ultra Balls are ideal, though if you take long enough Timer Balls might become feasible as well. Chucking Quick Balls right at the beginning of the fight might also do the job.

Thought he was done? Apparently not. Once you've caught or defeated the legendary Lysandre reappears, and he's wearing some bizarre new gear. Time for the REAL final battle with this weirdo.

Team Flare Boss Lysandre
  • Mienshao, level 49
  • Honchkrow, level 49
  • Pyroar, level 51
  • Gyarados, level 53
Reward: 10,600 P

Oh, so he's... just a bit stronger. Alrighty. Most of the battle against Lysandre is roughly the same as last time, with his Pokémon receiving a small boost in levels. They do seem more disposed to use stronger attacks this time, particularly Pyroar with Fire Blast, but three-quarters of the battle is nothing special. 

The battle only changes once Gyarados comes out, as Lysandre swiftly changes it into Mega Gyarados. This sounds nasty, but mind that Mega Gyarados is a Water- and Dark-type Pokémon, not Water- and Flying-type. Some of your attacks will lose their sparkle, such as Ice, while others - Fighting, Grass, Bug, and Fairy - will suddenly become rather effective. Gyarados still relies on Outrage for most of its damage, so prep your team accordingly. Dragon-types are not advisable.

A long cut scene follows once you defeat Lysandre. After that, yep, Team Flare is done for. Woo! With the local bad guy team out of your way you can get back to important business: Completing your Pokémon League challenge. You only have one more gym to go.