Lumiose City Pursuit!!
Funny how a dragon type pokemon rampaging in a city was a big plot point in Team Plasma's villain arc and then it happens again at the beginning of XY, but it is not related to any overarching plot. Both pokemon were being affected by a device designed to control them, by an evil group. Although in the case of Garchomp it was just goofy Team Rocket and they got blasted off, so not exactly the same kind of villains, but still...
Both use hyper beam and destroy city property.
In the case of Haxorus many more buildings were hit because it was being controlled by Team Plasma the entire time. Garchomp wasn't being commanded by anyone, so its attacks weren't necessarily directed at anyone. It was left to rampage on its own after it blasted Team Rocket.
In both situations a selfless character risks its well being in hopes of rescuing the pokemon.
In Unova, officer Jenny has already evacuated the entire city. Meanwhile in Kalos they are telling people to evacuate the area. Of course, the difference is that when Ash & Co arrived in that Unova city, the rampaging had already been going on for a while, in Lumiose they were there when it started.
I like how in the case of Lumiose City the news anchors flew in to cover the situation. For some reason nobody thought of doing the same in Unova and in retrospect I wish they had, so they could amplify how much of a threat Team Plasma was supposed to be.



















