Pokémon X & Y Cheats: How to obtain Banettite to get Mega Banette
Mega stones! You want 'em! We know where to find 'em!
First, keep in mind that you won't be able to find these Mega Stones until you beat the game and complete a slew of quests to unlock this ability. You can find the tutorial on how to start hunting for Mega Stones here.
To find the Banettite, you first have to find the Chamber of Emptiness. You'll need both Surf and Waterfall in order to access it. The quickest way to get there is to Fly to Santalune City. From there, head East toward Victory Road. Right before you reach Victory Road, head south and Surf. Head down the waterfall and enter the cave thats to the right. Congrats, you made it into the Chamber of Emptiness.
Besides finding a Spooky Plate, you'll be able to pick up the glowing Banettite in the North side of the cave.
Remember, the Banettite won't show up unless you touch the Sundial between 8PM and 9PM.