Defeat Metal Lord Mono-Han with 10 stacks of Power Surge.
This achievement is not as easy as it appears. In order to get a good start on stacking the buff, you'll need to kill three - if not four - of the electrocutioners at the same time. (Alayea and I found this out the hard way, as the buff kept dropping off before we could kill the next mob.)
VERY IMPORTANT: You must be in melee range in order to receive the Power Surge buff. Casters, this means you!
In the area that Metal Lord Mono-Han patrols are several electrocutioners busy electrifying... piles of stone. Don't be afraid to grab one of them to refresh the Power Surge buff during your fight with Mono-Han when he is spinning in place or otherwise not doing a special ability (which simply comes down to not standing in Bad Stuff).
It is so easy to keep the ten-stack that Alayea and I stuck to that area and farmed for Black Prince reputation.* Power Surge = Pew Pew!
*Your Mileage May Vary. At this point in time we had no competition at all for mobs because... there's a way in without having unlocked the area. No, I won't say how. Oh, and don't think you can get the Thunder-forge recipes early - Blizzard hotfixed Itoka so that he'll spawn only once the area is truly unlocked, I believe.
"Post constructively or I'll press some different buttons next time." -- CM Daeleht (from the old WoW website, no source link)
We also had the rep buff from the Darkmoon Faire Carousel, which helped a lot. And yeah, Itoka got hot-fixed out of the game until the stage area actually is unlocked (but not before some lucky blacksmiths got their loot).
Edit: Heard through various sources that at least one player that obtained the IoT blacksmith recipes got a 72-hr suspension and loss of the recipes. Ouch.
To gain this achievement, clear out the Shan'ze Electrocutioners working the forges outside the northeastern exit of Lightning Vein Mine. When you kill one of them, you gain Power Surge, so you must clear out 10 of them and then use the stacks of the buff plus your class cooldowns to kill Metal Lord Mono-Han within 2 minutes (max buff duration).