The Warden is a more healing and buffing version of the Fury. They have a wide array of regenerative direct heal and HoT (Heal over Time) spells. Wardens do have some damaging abilities, but they are primarily used for soloing and should only be used in group situations if there is a problem with dealing damage fast enough.
Like their Fury cousins, Wardens are able to wear leather armor. Even given this fact, Wardens should never tank or take damage, especially in group situations. If a Warden is the primary healer, he should be protected at all costs. Generally speaking, if the Warden dies, the group dies, with no ability to heal or resurrect any fallen members.
Wardens are able to use Hammers, Staffs, Symbols, Great Hammers and Swords for weapons. They are also able to use Symbols and Bucklers for shields. In addition to healing spells, Wardens are also able to change the form of their group into that of wolves, increasing their movement speed and damage done. They have a fair amount of group buffs, but not as many as Furys.