looks like there might be a reason to switch from rank1 drain soul in wotlk.
Originally Posted by http://forums.worldofwarcraft.com/thread.html?topicId=9679894204&pageNo=1&sid=2000#9
Drain Soul at level 71 will also do 4X damage against targets at or below 20% health
I was always hoping to get drain soul as a dot, something which does minimal damage, but last for a good 30 secs, just to make sharding that bit easier.
But im happy with this, it means i can actually use it as a proper damage dealer when killing the mob, rather than relying on whatever dots i already had on it, and having to time to it right. (destruction shard farming is just painful).