Bloodwinter Clan

so i did this quest Vision of the Dead and it gave me something that lets me see ghosts all over nagrand and while in negrand i get a mind vision type animation every 30 minutes on me which i think is the effect coming on again. now i have no idea wtf this is for! i cant find any special ghosts to talk to. i killed the boss in the next step and ended the chain. am i missing something? i tried searching for an answer but couldnt find one on any websites

There's a long quest chain in Nagrand that only opens once you do all the quests for the zone. After you do that you get a quest from Garrosh that starts the Thrall quest line and near the end of it you need to use some mirror on those ghosts and kill 15 of them.