Wanting to try the Ursan team.
Requirements:
5 people with a mix of  and (one or the other, not both).
1 person as earth tank with , probably better as a primary ele, with the following skills:

Core PvE only Arcane Mimicry 60 2 15 Spell. For 20 seconds, Arcane Mimicry becomes the non-Form Elite skill from target other ally. Core PvE only Obsidian Flesh 30 1 10 Elite Enchantment Spell. For 8..20 seconds, you gain +20 armor and cannot be the target of enemy Spells, but move 50% slower. (Attrib: Earth Magic) Eye of the North PvE only Glyph of Swiftness 10 1 5 Glyph. For 15 seconds, your next 1..3 Spells recharge 25% faster, and projectiles from those spells move 200% faster. (Attrib: Air Magic) Nightfall PvE only Stoneflesh Aura 15 2 10 Enchantment Spell. For 5..15 seconds, damage you receive is reduced by 1..31, and you are immune to critical attacks. (Attrib: Earth Magic) Core PvE only Mantra of Earth 20 10 Stance. For 30..90 seconds, whenever you take earth damage, the damage is reduced by 26..50% and you gain 2 Energy. (Attrib: Inspiration Magic) Nightfall PvE only Stone Striker 20 ¼ 5 Enchantment Spell. For 5..30 seconds, whenever you take or deal elemental or physical damage, that damage is converted to earth damage. (Attrib: Earth Magic) Core PvE only Armor of Earth 15 ¾ 10 Enchantment Spell. For 30 seconds, you gain 24..60 armor, but move 50..14% slower. (Attrib: Earth Magic)

Earth Ele UW Ursan tank

2 monks(anything goes as long as heals are done, be mindful of conditions, hexes, and interrupts).

Basically, if you're not running a monk, anything goes as long as you have either Arcane Mimicry or Ursan Blessing. If you haven't been to GWEN or done quests that far, go buy Arcane Mimicry. It's a core skill.

Idea:
The people that don't have Ursan Blessing takes Arcane Mimicry to copy Ursan Blessing. Note that you cannot copy Ursan Blessing if the target is already in Bear Form.
All 6 people will maul down everything while in Bear Form until special quests that require more thought, namely Servants of Grenth(the Ice King quest) and The Four Horsemen, where the earth tank will be taking the initial brunt(Servants of Grenth) or taking half the incoming monsters(The Four Horsemen).
The earth tank, especially as a primary ele, should remember that Obsidian Flesh used with Glyph of Swiftness will make the recharge time 22-23sec. Non-primary ele tank will have Obsidian Flesh last at most 21-22sec with 20% enchant duration weapon, primary ele tank will have it last 25sec, making a primary ele preferable as the tank.

Suggestion:
Everyone using Ursan Blessing(even the ones using Arcane Mimicry) would have the Bear Form last longer by using Zealous weapons. The -1 energy degen from Zealous won't take effect but you get +1 energy each time you deal damage, on top of +1 energy every time you deal and take damage.

Biggest dangers:
Unwanted Guests - If anyone runs toward the Reaper with the Vengeful Aatxes on your tail, that's a nono. Just stop and die there instead of doing that.
Servants of Grenth - A bunch of Terrorweb Dryders will popup. You will HAVE to dodge the meteor showers.
The Four Horsemen - It's not so challenging as much as the monks avoiding getting interrupted but still keep people alive. The people also need to dodge meteor showers here as well.


Approximate duration: 2-3 hrs, shorter side if Essence of Celerity is used.