We did a repeat FL+4, on the second try. He may become another hard mode we repeat Ad Nauseam, since the trash is technically shorter, and we get an extra item. Then Razorscale, to put a couple more notches in our frying pan. XT-Hard was one shot, and finally finally coughed up an Aesir's Edge.
We couldn't make up our mind on whether to do Iron Council Hard or Thorim Hard next, so we did a quick vote, and hit up Thorim. His hard mode adds more damage and health to him, and includes (fake) Sif running around adding in frost damage and snares. It doesn't require a ton of changes to the normal strategy as far as tanking or DPSing is concerned. Healers (who really are the ones most often challenged/shafted by hard modes) need to adjust for cleansing/dispelling frost novas, and healing the frost bolt volleys.
The screenshot is somewhat deceptive - we were doing awesome down till the last few percent... when I mistaunted (just a stupid move) and got owned. He then turned back to the other tank who soon took an Unbalancing Strike, and that spelled his end. Two DPS got taken out, but at that point we were just waiting for him to roll over to friendly-mode.
Feeling bolstered by our kill, we moved over to Iron Council. I'd read different accounts on if Molgeim or Brundir should die first, but we found Brundir dying first to be easiest. With DPS on him, people had easier times interrupting and running out of overload. We did have death runes to worry about in p2, but that was balanced by having a rune of power up for the first half of the all-important Steelbreaker burn.
Killing Molgeim (the second boss to die), was by far the hump to get over. I ate some powerful hits off Steelbreaker who got Runes of Power (more often) under him at this point, when he was already rocking damage increases from the first dead boss, and I was slow getting him to move out of them. I really just had to get on the edge of the hit box, have Molgeim as a focus target (to see his cast), and be ready to strafe the hell away from him (and his awkward hitbox) so he'd get out of the buff. You do have to move him way farther then you'd think.
On our first attempt we killed Molgeim, we won. I was on Steelbreaker first, and just was able to ride it out with my Indestructible Potion (that I'd used with ~1min left till Molgeim died, to get full effect), Last Stand, Stoneform, and Heart of Iron's procs. None of them really seemed crucial, though, with three healers on me.
The Overwhelming Power debuff he puts on you is pretty sweet. It reminded me alot of Burning Adreneline - you get double sized, and start putting out some serious damage. We had him to ~30% before I blew up, in part due to Molegrim's lingering rune of power + heroism. Taking out the then remaining 40% in the following minute was cake (ot at least seemed like it, from my vantage point). Our other tank was even so benevolent, that after the boss died, he ran to a safe place to meltdown (instead of playing hug-the-raid).