First time I did BM - normal mode - I had a healer who normally did Heroics, but needed rep with Caverns of Time; almost all of the instance, the ride went smooth... I informed my party members that I need to charge at a wave with full mana, to be an effective AoE tank (I couldn't picture leaving trash - worth their weight in gold for any tankadin - to a DPS). Everything, until Temporus... Maybe it was a bug, maybe I was undergeared, maybe it was bad luck... I got 7 (SEVEN) debuff stacks, each applied when the others had 2, maybe 3 seconds until they faded away. The healer - a shaman - was throwing all he had at me, but the debuff stack made heals look like Linen Bandages. At about 60-65% of Temporus' HP, he said "dude, just die... I'll be OOM soon; let the druid tank". I didn't have much of a choice there, so I kicked the bucket and the druid bear stepped in - it took a little longer, with only 2 other DPS, but I never saw that debuff stack more than 4 times on the druid.
Ever since that first time, I never had the debuff stack more than 4 times either. I tend to see it as bad luck - Blizz does say the bosses have CDs on spells/abilities, but don't necessarily use them whenever possible. Other than Temporus, I had no issues with this instance.
What you should try, given good gear and some disciplined party members, is to always drink between waves, mount up with the aura and rush the portal just as the first adds are spawning - so you can make full use of AS -, and try not to let any mob past you... They'll most likely complain you are stalling and two waves will likely overlap and wipe the party, but having full mana gives you enough consecration spells to mop up the adds, while allowing your DPS to constantly hit the Rift Lord/Keeper/Bosses.
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'The world is grown so bad, that wrens make prey where eagles dare not perch.'
