Master Illusionist: Active: Shroud you and your party members, regardless of location, in illusory magic that disguises their location. They gain 95% Concealment for 15 seconds. Cooldown: 3 minutes Passive: +2 Intelligence, Wisdom and Charisma. +2 Illusion DCs. Note: That the 95% Concealment will be shown as Blurry during combat, despite Blurry normally being used to represent 20% Concealment only.

lets do some math ..

15 seconds ..
12 people

by golly gee thats 3 mins ..

what ever you do .. dont show up to a raid with with 12 people all with 41 points in the fay tree..

humm..