While I know an article on the subject may pop up on the main site at some point, given the time-restricted nature of both the event in question and the game itself, I wanted to let those watching the blogs know what's up in the Pokémon Shuffle world right now if they're not playing regularly.
Spanning from April 6th to April 13th, Pokémon Shuffle players can take part in an event very similar to a previous timed event in which you can battle it out against Mega Blastoise! The top 20,000 ranked players in the US, the top 10,000 players in the EU, and the top 50,000 players in Japan will all get Blastoise's Mega Stone as a reward, while everyone else gets a free stone, which is still nifty for just turning on the game and doing a one minute stage.
If you're far enough into the game, consider playing some of the EX stages and picking up Sceptile, Zapdos, and Raikou for your team, or just whatever else you have on you that works, though be warned, you... probably won't rank even if you have them. I only have Sceptile and Zapdos myself.
Did I mention this has surpassed three million downloads recently yet not even 100K people can win this thing? Good times!
On the bright side, you still have until April 20th to catch Rayquaza, and your first completion of the stage will net you a free jewel.