Class

Demon Hunter

Shuttered Soul · levels at 2 / 4 different pieces

Every Demon Hunter piece: Each Demon Hunter counts as an extra Demon type for the enemy, which can break their single-Demon (Fel Power) bonus.

2
Your Demon bonus stays active no matter how many different Demons you field, and enemy Demon Hunters can't break it. Fel Power stacks count every friendly Demon plus enemy Demon Hunters (max 7).
4
All allies deal pure damage. Physical and magical damage is turned into pure damage at its full value, so it ignores armor and magic resistance.
Note: The tooltip doesn't say that damage is converted before armor and magic resistance, so armor and magic resistance reductions (Hunter, Mage) no longer add damage.

Official in-game tooltip

Counts as a different enemy Demon type.

CLASS PERK: Shuttered Soul
Active when you have at least (N) different Demon Hunter pieces on board. (Multiple effects stack)
(2) Demon Hunters: All friendly demons are considered the same type.
(4) Demon Hunters: All damage dealt is settled as Pure Damage.

Demon hunters ritually trade their normal form in exchange for the mastery of demonic powers that enables them to deliver devastating strikes to their prey. This enhanced strength, together with their great agility and magical prowess, makes demon hunters unsuppressible.

Often paired with

Races and classes that Demon Hunter pieces also have, with how many share each.

Demon Hunter pieces (4)