since Inner Fire got fixed (not nerfed

this is in HM, run can be done in approximately 10-12 mins, depends on the time you spend killing the last few stragglers

in NM, it can be done in around 6-8 mins, and if you're going for cores, it's probably better to do it in NM
builds :
hero : Ranger/Monk
[skill]quickening zephyr[/skill][skill]serpent's quickness[/skill][skill]blessed signet[/skill][skill]mending[/skill][skill]watchful spirit[/skill][skill]balthazar's spirit[/skill][skill]greater conflagration[/skill][skill]winter[/skill]
16 wilderness
8 healing
rest in expertise
(yes it has mending

sometimes in HM some damage will slip through, so I took those as a safety valve

greater conflagration and winter are only useful for mes and ranger I'd say
give him/her any staff with +15 or +20 energy
you : Any/Ele
[skill]glyph of elemental power[/skill][skill]obsidian flesh[/skill][skill]stoneflesh aura[/skill][skill]armor of earth[/skill][skill]sliver armor[/skill]Alkar Alchemical Acid Elemental Lord
last slot is variable depending on your primary
(watch out it's not kinetic armor it's armor of earth

in any case you need 12 in earth
having high dwarven rep helps, but I think it's not mandatory, since your main damage is cracked armor + sliver
Mesmer primary, take [skill]mantra of frost[/skill] (tested in NM and HM)
12 inspiration
balthazar spirit not needed but needs winter/greater conflagration from hero
Ranger primary, take [skill]storm chaser[/skill] (not tested)
12 wilderness
balthazar spirit not needed but needs winter/greater conflagration from hero
Warrior primary, take [skill]bonetti's defense[/skill] (not tested)
12 tactics
instead of a shield, you can try with an earth focus with +15/-1 to boost your energy pool
Necromancer primary, take [skill]signet of sorrow[/skill] (not tested)
12 soulreaping
Monk primary, take [skill]shield of absorption[/skill] (not tested)
12 prot
Ritualist primary, take [skill]vengeful weapon[/skill] (not tested)
12 restoration
Assassin primary, take [skill]dark escape[/skill] (not tested)
12 shadow
Dervish primary, take [skill]dwayna's touch[/skill] (not tested)
12 wind
(lol dwayna touch image is upside down ^^)
Paragon primary, dunno, it would probably work with anything (not tested)
energy might be tight
as you can see I only tested on my mes, but I guess it should work also for other primaries, feel free to test the other primaries and let me know if it works in NM/HM
equipment :
axe/spear/sword +5 energy 20% enchanting (use one with 10% furious if warrior primary)
max armor shield whatever the req (+8 armor)
also you'd want +10 armor while enchanted insignias, but I did without
the run :
start the challenge from central transfer chamber
run with the hero to the baby dragon, flag hero there, and cast the needed enchantments on you
walk approximatively 1 aggro ahead (between the 2 rangers npcs)
wait for the destroyers to come, as the first destroyers aggros the dwarven npcs, start casting winter and greater conflagration if your primary requires it (mesmer/ranger)
precast glyph of elemental power and elemental lord, serpent quickness then quickening zephyr
cast obsidian flesh when there is only 1 ranger alive left at each side, then stoneflesh and armor of earth and whatever skills from your primary needed to survive
be sure to recast quickening zephyr as soon as it recharges at first
keep up all the enchants (obsidian flesh, stoneflesh, armor of earth) and wait until approximatively 3 minutes, all the destroyers should have arrived
walk slowly from left to right to be sure to have aggroed EVERY destroyers, don't let them slip through or your run will be ruined
in case one manages to get through, you probably will have the time to kill it before it kills the dragon, quickly walk up to him and use alkar alchemist acid then sliver armor
otherwise walk up to either group (left or right), pick one target and use alkar alchemist acid then sliver armor, repeat until this group is dead, pick up loot and proceed with the second group with the same tactic
when there is only 1 or 2 left, you could simply resign and start again, but with chance you can kill them, it's hard if it's the ranger since he has high armor vs earth damage :/
you get in average 2 cores per run (dualing kills a bit drops I admit

but this is about the same as dualing with VwK (VwK being faster though)
inputs are welcome

cheers