Many "weak" Pokémon have been given stat boosts, new abilities, or updated typing to make them viable.
You don’t always need to "hard patch" the ROM. You can right-click Pokémon Y in Citra, select "Open Mods Location," and drop the Wilting Y romfs folder inside. Download Pokemon Wilting Y
Most downloads come with a PDF or Excel sheet listing wild encounter locations and evolution changes. Keep this open! Many "weak" Pokémon have been given stat boosts,
If you have Luma3DS CFW, use the "LayeredFS" method. Place the hack files in luma/titles/[TitleID] . Tips for Surviving Kalos select "Open Mods Location
Pokémon stats and types remain unchanged from the official games.