Q&A for How to Evolve Scyther

Yes, you can. After completing the main story, you receive the Key Stone and Alakazite from Dexio. To acquire other Mega Stones, reach the Battle Tree on Poni Island after defeating either Red or Blue; you can then earn Battle Points (BP) from challenges to purchase them.

For a complete list and visual walkthroughs of all Mega Stone locations in Pokémon X and Y, you should search for guides on platforms like YouTube.

If your friend doesn't return your Pokémon after a trade, it will be lost. To prevent this, only trade with someone you fully trust, or use two separate game systems and copies of the game yourself.