I'm not particularly surprised this happened. Aeria's lack of control over the events and prizes (for the most part) is very obvious and similar things have happened in Caesary as well.
Like marksteele said, having an event that made such a big deal out of attaining these Mystic Chests and the E-Weapon inside for the few top players then having an event that made these same weapons available to every player with little effort is a slap in the face. Not only that, but made it possible for players to attain more than one Mystic Chest.
Now you can say that this is a chance reward, that only some players will gain access to these weapons but the problem is that the 3 people who worked hard to get those weapons have now been joined by 30 or more players who just spent a day to get a few medals. Some of those players have more than one.
What this leaves us with is a few Energy Stones and number of useless Pearls. Every pearl I opened was level 1 and I heard similar things from the other top two. The Stones I received got me a +5 outfit and upped my Gulu Shield to +4. So basically my few weeks of work let me get something I could have already done if i have bought lv4 energy stones instead of experience pills.
Let me be clear though, the Halloween event is awesome, especially the costume trading part (from Gulu). I love events that give everyone a fair chance and are fun at the same time; good rewards and can't simply just buy the event. Of course it could be better, as all events can be but its a good event nonetheless.
The problem comes in the timing. Thanks to the Halloween event, players had the top prizes from the Leveling and Power events before the top players even received their rewards. I already had an E-Weapon before I was paid out. Other people had 3. I spent weeks leveling and grinding my way to the top and then find out all the prizes I received were rendered pointless or were completely useless. Not to mention the 2x glory item was glitched.
This is yet another example of how poorly this game is being treated. Not only do blatant users of exploits get a free pass and a written guide, but those players who have worked their butts off and are major supporters of the game get ripped off, our prizes rendered meaningless.
This is not the way to run a game or the way to treat your players.