Heroic 2-6 experience or mystery strangers farm

This is a fire team that is capable of clearing all of 2-6 heroic, especially the earlier combat nodes, so it is especially good at farming mystery heroes or experience. Here is recommended ability levels and equipment:

• Alexstrasza
  • Dragon Breath {0}
  • Alexstrasza's Brooch 2 (level 2 or better)
• Baron Geddon
  • Inferno {0}
  • Mark of Conflagration {0}
• Ragnaros
  • DIE, INSECTS! {0}
  • Sulfuras 2 (level 2 or better). Ragnaros is very squishy and the health boost here is important for him to survive turn 1 burst or bad RNG.

The only decent replacement for this team is Antonidas in place of Alexstrasza. His fireball is the perfect trigger for the Inferno combo, but he's less durable and not as flexible since you're losing the healing on Dragon Breath.

From here all you need to add is a Mystery Stranger task recipient and then take two lowbies to gain experience.

Combat

The strategy is very straight forward. Queue Dragon Breath {0} before Inferno {0} since they are the same speed, and you need Dragon Breath to go first to trigger the fire combo damage on Inferno. It doesn't matter if you use Dragon Breath for healing or damage, it will trigger the combo. Also with this in mind, avoid picking up any treasures for Baron Geddon that reduce his abilities' speed since that may lock you out of being able to trigger his fire combo on Inferno. More often than not you are just using Fire Breath on the highest level target and then Inferno and DIE, INSECTS! finish the job. Sometimes there's a round two but it should always be cleared by round 2. If any bad RNG or anything happens don't forget you use Dragon Breath to heal.

Just adding a little bit of maths, with my build listed you're doing 8+13 + 22 non-critical AoE damage so that's 43 damage total to casters, and protectors and fights will take even more from Baron and Rag. You're also getting 17 damage from Alexstrasza on a single unit to use her to push anyone who might live into the AoE kill zone. Of course this gets easier when you pick up + fire damage treasures. You can also take Ragnaros's fire damage equipment which will give you 11+16+22 = 52 AoE damage which looks like a no brainer, but a 64 HP Rag can easily be sniped on bad RNG or if you get stuck fighting a caster x3 team., and I find I don't have any problems with my 43 AoE damage setup.

Banehollow - This team can beat him easily if you want to grind Anduin coins or get his experience which is also pretty good for heroic mode. Nearly the same rules apply with spamming Dragon Breath, Inferno, and DIE, INSECTS! Just keep an eye on what abilities they are using and use Dragon Breath to heal if needed, but Baron should nuke them in 3 turns. Remember it's the last fight so it's okay to lose Alex or Rag but keep Baron alive or you'll have a tough time finishing the fight.

Mystery Strangers

This map can get decent nodes in 1-3 fights so reset as needed if you are just interested in task farming. If you are doing actual tasks (opposed to consolation coin farming) the fights here are actually good to finish those since there are Imp's that do zero damage and give someone next to them extra health every turn. So some of these are perfect for finishing damage or healing tasks.

Unit Leveling

Maybe you got a lucky pull from a Mercenaries pack crafted a brand new mercenary for your dream team and you just want them to level to 30 asap. Heroic 2-6 is a perfect place to do that for lightning fast experience. Focus on the Elite fights, and you'll level in no time. Banehollow gives about the same XP as an elite fight but I only find it worth it to kill him if I'm naturally brought close to him in searching out other elite nodes or run into a portal. Just take a good path through elite nodes and reset. I find it efficient to still prioritize Mystery Stranger nodes and hit elite fights on the way or that maybe in the very next node after it, that way I'm still getting coins for my time leveling, and you'll get to 30 in no time.