Spirit Shrouds allow you to take on the form of a creature of Norrath and adventure throughout Norrath from this creature’s perspective. The creatures you may become are limited based on your main character’s current level and consist of a number of class roles, such as healer or melee classes.
Spirit Shrouds offer a unique way of joining your lower level friends as they adventure, or of balancing out the class composition of your groups, all while still earning experience for your main character.
To don a Spirit Shroud, you must speak to a Shroudkeeper in Plane of Knowledge, who will present you with a choice of creature forms to assume.
As you play with Spirit Shrouds and earn experience, you will also earn points toward unlocking more Spirit Shroud creature choices. Each creature form has different abilities, strengths, and weaknesses that will be displayed in the selection window.
You may leave your creature form and return to your main character at any time by returning to the Shroudkeeper.
(Info copied from the former SOE Knowledge Base.)