Casts heals and debuffs. Summons ghosts to do damage.
Dark Revenants use special Bells to summon ghosts. Therefore they use Bells as talismans, which have special enhancement charms on them. Dark Revenants can enter a Soul Form, where instead of using their spiritual powers for healing, they can summon ghosts to add Debuffs to enemies.
With a strong Debuff ability, Dark Revenants are more like single-target strikers than healers, though they can still carry out those duties.