Last night we were trying to run Hardmode EC and noticed a problem with Firebrand and Stormcaller. The Double Destruction mechanic was using the Nightmare Mode mechanic instead of the Hardmode version. Our players were getting the extended debuff and causing us to die earlier than expected. I would have to guess that this was inadvertently changed with the patch yesterday. Please fix this so we don't have to run Nightmare Mode tactics in Hardmode.

If I remember correctly debuff was extended many patches ago. you just have to push enough to only get one DD per shield phase, which is simple with current gear levels.

We ran this as recently as last week and weren't getting the extended debuff then. It was new this week.

Are you getting a second double destruction? If so your dps isn't high enough to use only two people per shield cycle. If this is so, you will need four people for two separate double destructions. After a dps or healer get hit by double destruction, they shouldn't take any more damage unless they're getting cleaved. Edited July 24, 2013 by Falver

What matters is the DPS on Stormcaller, start with all your raidgroup on him and then swap half to Firebrand after first DD, should make sure that he never ever makes two DD during the same phase.