I caught pretty much my first shiny in Pokemon Y (a Cubchoo) today from a horde. The very first shiny I encountered was in Safari, but the odds of finding one there are much easier.

EDIT: A couple of the Pokemon I used in Pokemon Y are now listed as Ubers (Mega Mawile/Aegislash). Should I avoid using them for now on or is using one on your team okay? I read using one on your team automatically makes your team Uber so I don't know.

If you are using them for the ranked VGC battles on the actual games, it doesn't matter since they don't follow Smogon rules, however most tournaments (Non-Nintendo Hosted) or player battles will follow the Smogon format since it'd typically the most balanced setup compared to VGC rules. Personally I prefer people following the smogon tiers and rules to prevent unfair plays.

Smogon system has the whole tier systems and sleep and species clause etc.

VGC is the system Game Freak made up that's basically all legendaries are banned and you can't use more than one of the same item on a team and more than one species, everything else goes.

Also horde shinies are as common as the safari since you are encountering 5 at once so your odds are pretty much x5 more than usual encounters.

I try to follow Smogon rules since they seem fair and balanced. I should have figured finding a shiny like that so easily would be too good to be true. I guess I'll trade it or something.

It's actually not too hard to get shiny pokemon in this game. You can do something called "chaining" (gonna have to look it up) and basically get whatever shiny you want in about an hour.

lol wow killjoys

So I went with Bulky Swords Dance Mega Scizor and noticed he dies in one hit from a physical fire attack. Who should I have on my team to help counter fire?

Oh yeah. That Pokemon that one hit KO'd him was Talonflame which I had knocked its choice band off before it attacked me and still one hit killed me.

Scizor is -4x to Fire, he is rip from every fire attack. Best counter to tflame is Flash Fire Heatran by a landslide. Any rock poke makes talonflame rip too.

I'd love to use Heatran, but I can't breed it and getting my hands on a non-hacked one would prove to be inefficient. I read that Tyranitar is another good counter for Talonflame with its stone edge and being resistant to fire and flying damage. I'm not entirely sure what I'm doing so far for my team, but right now it consists of:

Jolteon
Nature: Timid
Ability: Volt Absorb
Item: Life Orb
Moves:
- Thunder Bolt
- Volt Switch
- Shadow Ball
- Hidden Power (Ice)

I love using Jolteon to take out Gliscor users. HP Ice has always been a 1 hit kill for me against him.

Dragonite
Nature: Adamant
Ability: Mulitscale
Item: Weakness Policy
Moves:
- Dragon Claw
- Extreme Speed
- Earthquake
- Dragon Dance

Scizor
Nature: Impish
Ability: Light Metal
Item: Scizorite
Moves:
- Knock Off
- Swords Dance
- Roost
- Bullet Punch

Rotom-Wash is also a good counter on fire types. Plus it's easy to obtain and breedable on X and Y.

Any Stealth Rock poke can take down a Talonflame.

True. Hmm...

If I were to lean toward Tyranitar I would throw an Assault Vest on it, but if I used Sandstream on it my other Pokemon would suffer greatly since Dragonite has Weakness Policy and Jolteon has the Life Orb. Would it be bad to use Unnerve for my Tyranitar instead of Sandstream? I should probably consider Rotom-W and some other options if that is the case.

A tyranitar sandstorm matched with any focus sash, sturdy or multiscale poke will greatly hinder them. Having unnerve is a decent choice but not optimal since the only ones that runs berries are probably Sitrus berry belly drum poke or chesto resto super stalls which is not too common on every team. Especially this meta is all about those hard hitters with no reliant on berries over Life orb and choice.

Not Tyranitar it is!

I battled a Mega Mawile today that totally destroyed my Mega Scizor with fire fang in one hit. Then, even with multiscale it was able to bring my Dragonite down to 1 HP with Play Rough. After that it used Thunder Fang and took out my Empoleon.

Wait why light metal on scizor? Having technician on it would be way more beneficial as it gives a big boost to Bullet Punch and other <=60 base attacks.

Mega Scizor automatically receives technician and I plan to have him enter his mega form as soon as he is ready. While switching him out I read that light metal reduces damage from low kick and grass knot.

Oh sorry, didn't notice the scizorite, just skimmed through your build.