It can still be utilized after respecing out of the passive points if you had run a monolith or zone inbetween teh time of respecing. It is 150% dmg every 3 seconds with full spec into the passive tree and it does not stop after despecing if you run a zone instance. will be streaming on Twitch at 3:20 pm to verify the bug and its existance.
Do you actually get the damage buff? There is a graphical issue where the buff icon doesn’t get removed if you have it then respec the passives but that doesn’t actually give you the damage buff.