Ardent Custodian

Ardent Custodian is a main-hand mace with bonuses for tanking.

This golden mace is designed for defense, not offense. When held, it substantially increases the wielder's staying power in combat, but adds no fighting ability whatsoever. No self-respecting warrior would carry such a thing, but it is a favorite among healers and other classes known strictly for combat support.

Source
This item is a world drop.