I joined a pug 25-man Obsidian Sanctum last night, just for the hell of it. The RL had confirmed that they were going just for completion, 0 drakes up, so I thought it'd be an easy ride and sure enough, it was.
I'd done 10-man OS a few times before so I knew the score, what to do, etc. 2nd drake was a little frought because it was ninja pulled while we were clearing the patrol and then not enough people went in to clear the eggs but we came through it. 3rd drake was the usual piece of cake and then came Sarth.
From 10-man, I've learnt to swap from the usual DP/WP combo to Anaesthetic poison on both and this time I was well glad to have it - the second set of flames got caught in a lava wall and enrage for a couple of seconds and the Fan of Knives calmed them down. I just love that skill.
I went back to Sarth for a couple more lava walls and next time I turned round to see what was happening, there were about 10-15 flames converging on the OT. After he hit consecrate, I hit Fan of Knives, spammed it and it spammed me. I don't think I've seen so much damage coming out of my hands at once.
The Overall Damage charts backed up this observation. For the whole run, I averaged around 2500 dps (4th overall) but on the boss I scored a whopping 3000 dps, 2nd to the RL - a fury warrior.
No drops for me but damn, FoK is FoK'ing great fun.