Lysandre's Reckoning

No sooner had I caught Yveltal than Lysandre barged-into the door to try to steal Yveltal back from me.  This was the first instance of real hand-to-hand human conflict in the pokemon series and I was surprised to see Lysandre use his obvious height and size advantages to his benefit to just take the pokeball out of my hands after beating me up.
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Nah, I'm just kidding, he challenged me to a pokemon battle instead.

I had the option of using my newly-caught Yveltal.  Remembering how much trouble I had against Mienshao in my last fight, I took the Flying-Type advantage of having Yveltal in my squad and sent Ziggy the Linoone back to the box.
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Yveltal is Dark/Flying, so Mienshao's Hi Jump Kick dealt about 60% damage to me right off the bat, but I knocked him out that same turn with Oblivion Wing, a powerful Flying type move.

Next, against Lysandre's Pyroar, I sent-in Greninja, who was too slow to move first.  As a result, it had to eat one of Pyroar's Hyper-Voice attacks and survived it with exactly 1 HP left (wow).  Water Pulse did about the same amount of damage to Pyroar, but I was able to pick it off by using "Water Shuriken", a move which always moves first.

Pikachu took out Honchkrow in one hit, and then stays-in against Gyarados.  This is Lysandre's final pokemon, and I knew that Pikachu would move first and destroy that Water/Flying type with a powerful Thunderbolt move.  But Gyarados did the unexpected.  Gyarados evolved into Mega-Gyarados.

This is the point where the tide of the battle begain to turn.  Gyarados tanked Pikachu's Thunderbolt--only taking about 50% damage (this will be important later on)--and one-hit-KOed Pikachu with Earthquake.  I sent in Hippopotas to try to whittle its health down with sandstorm, but he was taken out in one hit by aqua tail.  I sent in Venusaur hoping it would survive enough to poison it, but poisonpowder missed and Venusaur died on turn two of Gyadaros' outrage.  Mega Lucario was next.  Mega Lucario was LAST.  It was over, Lucario just couldn't hit Gyarados hard enough with Shadow Claw and my fighting-type moves will be too weak.

But wait a minute...flashback...

"...Gyarados tanked Pikachu's Thunderbolt--only taking 50% damage..."

Exactly half damage?  Could it be?  When Gyarados evolves, is it no longer a flying type?  Will Aura Sphere still work?  I take a chance with aura sphere:  super effective!  Mega Gyarados is Water/Dark!  KO!