This is just a list of my ideas for events in Pokemon X and Y
Jirachi Event Edit
If you start up the game in the event period and go to Mystery Gift settings, you will get a special ticket from the internet. The ticket is called the Comet Ticket. Upon entering the game and obtaining the ticket, you will be taken to the train station by Professor Sycamore. The ticket will take you to the Millennium Comet Festival from the 7th movie. Once here, you can do many stuff, but you are pointed to a man that is taking making tours. He will take you to a small forest grotto. At the center, you will find a large meteor. If you interact, it will tell you the meteor opens up for 12 hours only, and it will then show a timer with 7 days on it. You can now fly here. If you come back to the area in exactly 7 days, for 12 hours, the rock will glow. Interacting with it will initiate Jirachi's appearance, he will go into your party or pc
Heatran Event Edit
After starting up the game and going to receive your Mystery Gift, you will obtain an item called the Vullca City Newsletter. Once you receive the Newsletter from the delivery woman, the letter asks for a strong pokemon trainer to help with a problem in a far away Vullca City. It tells you to meet them at the Couriway Train Station.