Some of these items might be covered in other thoughts, but I would love to see these 2:

Elemental-Magic Tank
Weapon: a handle / hilt / grip. The tank would imbue the grip with one of the elemental affinities. it would create the weapon and add a benefit/debuff (10% chance) if there was a critical hit on the mob. Their skills would be the same for all the weapon types, but attuned to the elemental affinity.
  • fire weapon = burning debuff
    ice weapon = slow debuff
    air weapon = attack speed buff
    water = heal over time buff
    electricity = shocking debuff (paralysis)
    earth = defense buff

Chanter/Aura Healer
Weapon: Shakujo (Buddhist ringed staff) They would chant/use aura to heal those in close proximity to them (melee healer). Their main heals would be in the fact that the auras/chants are up almost all the time(max 2 auras). A visual aspect of the chant finishing would be the tap of the staff on the ground and the rings chime.