The recommended and ethical method is to apply the patch yourself. This requires you to own a legal copy of Pokémon Y (a cartridge or a digital copy from the eShop). You dump your own game cartridge to your computer to create a clean ROM, and then apply the Neo Y patch to it. This creates

The modder behind Neo Y took liberties to balance the competitive viability of weaker Pokémon. Certain Pokémon received base stat buffs, while others had their types altered to make more sense (often aligning with later generations' retcons or fan theories). For example, a Pokémon that was previously useless in battle might now have the stats to be a viable team member. This encourages players to experiment with creatures they would normally ignore.

Avoid YouTube videos promising "direct download links" to pre-patched ROMs. Many are scams, viruses, or outdated beta versions. Stick to patch files from reputable forums.