Mass Healing is a Bhaalspawn ability that can be acquired in Baldur's Gate II: Throne of Bhaal if one has either the Unfinished Business (Baldur's Gate II) or Ascension mods installed. It is essentially an improved version of the level 5 Cleric spell Mass Cure.
When using this ability, the Bhaalspawn must picture the faces of his fellow party members clearly and focus on the unity of the group. Upon completion, all party members within 30 foot radius of the caster are healed 2d8 + 2/level hit points. Other conditions suffered by the party are cured, as well: fatigue, poison, disease, blindness and deafness.