Haven't tried heroic yet but I found a spell-heavy mage, plus a couple of flamewakers, did great for the first two bosses. Atramedes I took out with a freeze mage with two Snowchuggers and two Water Elementals. I never needed to reset his weapon as I got to freeze him every round with a snowchugger or elemental!I used a slight modification on my Hunter Deathrattle deck for Nefarian with an added Harrison Jones. Took a few tries (unlike the others) but I got him in the end! Harrison scored big on Onyxia's weapon :DPaladin challenge was a hoot.Dragonkin Sorcerer can be pretty neat with all the paladin buff spells!
Used Grim patron for the first two bosses for an easy win. I got Atramedes with a control paladin and Nefarian with Dragodin. Pretty easy one try fights for the first three bosses. Nefarian can be a terror with all his huge minions, but it's doable. You just have to pay attention to the timing of your summons and damage output on both sides of the board.
Ah, after having to deal with heroic Chromaggus last week (I eventually ended up winning by cheating out a fairly late Mal'ganis with Void Caller, then buffing the heck out of him with Demonheart and Demonfire), it was somewhat nice to return to fairly easy heroics - though, as a whole, BRM has had pretty easy heroics - I felt like the difficulty overall was much lower than H-Naxx, but that's very likely due to it having a similar difficulty (to allow newer F2Pers to have some sort of chance to win), yet a lot more cards being out now (so those with sizable collections have even more strategy options now).In any case, for the heroics this week (this should also extend to the normals):Omnotron: if you have the deck available, this guy makes Antonidas' infinite fireball combo in mage a cakewalk. 2 of his bots directly help mage, one doesn't really hurt nor hinder (Toxotron), and the expensive one is a nuisance. Basically, all you have to do is get to turn 9+ while Omnotron has out the -3 spell cost minion, drop Antonidas + one Sorceror's Apprentice, and cast a solitary spell to get your first Fireball.Board removal becomes a lot easier with the -3 cost and +2 spell damage minions, and you may very well consider leaving the -3 cost one up given that it makes many useful spells - Polymorph, Fireball, Arcane Intellect etc - a lot cheaper. Basically, stay alive, stall, clear as you need to (you may have to kill the -3 cost minion, but if you can live a few turns he should get it back eventually) and then put out infinite Fireballs. This may have been the easiest heroic yet simply because of how much his minions help you.Maloriak: this was, IMO, the hardest heroic on the wing. While the health/attack switch isn't really an issue, giving all minions +2/+2 is quite painful. However, his removal isn't great, and your health will sink enough that you can play Molten Giants for cheap - as such, Molten Giant + Sunfury Protector/Defender of Argus is great. Personally, I played a warlock variant, as Power Overwhelming + Shadowflame also offers you an incredibly powerful one-sided clear.Atramedes: another pretty easy one with mage. 2x Snowchugger, 2x Water Elemental, 2x Acidic Swamp Ooze and Harrison Jones gives you 7 options for handling a weapon that gets too big. Beyond that, just go with typically midrange mage cards. I can't recall if you get the weapon-destroy spells in heroic (I feel like you don't), but in either case, didn't need them at all.Nefarian: while not the easiest fight in BRM, he's another that falls prey to the Antonidas fireball combo. The only issue is that when he lands after you kill Ony he'll clear the board, so you have to be prepared. Personally, for me this preparation involved casting my second Echo of Medivh one Fireball before I killed Ony, so that I'd get 4 more Sorceror's Apprentices in my hand for a second go of the combo (I killed off Antonidas before casting it, as getting him in hand + another Fireball would have put me to 10 cards, but more importantly, caused me to miss out on an Apprentice). While I could have just played out Antonidas + Frost Nova on the next turn and hoped he lived (a good chance), I ended up drawing Thaurissan which, after reducing all my spells by 1, meant I could play out the whole combo in a single turn.Interestingly, 6 out of 17 heroic bosses in this adventure could be done fairly easily with freeze/combo mage (with tweaks depending on the fight, of course). I wonder if that's too much...