It took quite a few tries as we refined a strategy that worked for our group, but we finally killed Lady Deathwhisper. We had killed her on 10-man but she was looking nigh impossible in 25-man mode where we've been having quite a bit of trouble with progression the past few months. That was until we put our heads together and came up with our own strategy that had us line up behind the boss and split the raid up so that an equal number had responsibility for either side. One group would be responsible for the adds from the left, and the other group would be responsible for the adds from the right. And we would give priority to killing the adds. So after the initial few seconds of DPSing the boss, everyone would kill their sides adds and have about 10-15 seconds to DPS the boss before the next wave of adds would come out. We have two hunters in the raid, so they were given the responsibility of kiting and killing the Deranged Fanatics, though you could do that with a Mage, Balance Druid, Warlock, or any other really hard hitting ranged character. The tanks would remain aware of which type of add came from the back and would pick it up if it were a Fanatic, and the melee in the raid would kill it if it were a caster.
With only a couple weeks left before the next wing is to be released I was very anxious to make progress. We definitely have Marrowgar on farm and it now looks like we have a very clear idea what we all need to do on Deathwhisper as well. I'm personally looking forward to seeing the gunship battle in 25-man because I've found it to be quite fun in 10-man mode. I'm curious how different it might feel in 25. And it's just a good, fun fight.