Armor Spam Invul, Bleed Nimiod

Nimiod as his chain primary attack + lots of nodes can quickly deal with high level enemies, even if their damage reduction rounds your damage per hit down to only 1 damage, the huge amount of damage procs going off still quickly clears enemies and even bosses.

For damage:
Using neutral element for bleed proc, as fatal wound is too good to pass up on for a build that procs so many damage instances.

For tanking:

As nodes are counted as minions for together strong. And we can spam nimiod's tertiary (melee) ability for warm up strike to give you infinite free nodes. Node cluster also has a huge benefit here.
Upper limits?
In theory if player properly you can always have at least 4 or so armor stacks, and take this to any level.

Dangers:
Enemies with the poison aura will tick very frequently and still deal damage through armor, other than that just be careful to not move away from your nodes and take big damage, this build has no healing.