Bumping this because there's a 3rd relevant way to do the personal achievement.
3) Collect a shard from each dragon by purposefully eating the frontal AE on all your toons. Most of the time, you have to wait around for a while before the dragons do their frontal AEs. Frankly, I had to use staunch recovery the last couple of times I've done this because both my healers were like "wtf?" Once you have a shard from a dragon, kill it and move onto the next until you have all four shards and all four baby dragons are dead. I hope you didn't use burns because now we burn Vulak. Burn vulak down and then move your team to the zone-in area while the golems path to the center (assuming you managed to kill Vulak before the golems arrived and fucked your world). After all the golems are down you're now standing there with everything dead, BUT, the auras are still up because you haven't clicked the middle thingie yet. Run around to each of the auras and use the guide @ABWar posted
>> above << to click the right shards in the right auras. Make certain you run into the middle of the aura, target yourself, click the shard, and WAIT UNTIL YOU SEE THE YELLOW TEXT SAYING YOU WERE SUCCESSFUL. Now you can move out of the aura and go to the next one. Rinse and repeat until you've done all four corners. Move to the glowing center stone/column thingie and click it for the mission win and for chest pop. Congrats, you're done the personal achievement.