This skill can only be used in PvE, and is unusable by heroes.
There is a duplicate of this skill for both Kurzick and LuxonAllegiance rank. They differ only in appearance and in which Allegiance rank they use for their progression. You may equip only one of these duplicate skills at a time.
If you attempt to summon your spirits through impassable terrain, such as a closed gate, the healing effect will still apply, but the spirits will only move to the closest spot allowed by shadow stepping restrictions (e.g. just on the other side of the closed gate).