"Re-create this historical War in Kryta bounty quest. Greves the Overbearing called for a crusade against the Temple of The Ages and spread much misery among worshippers of the Old Gods during the White Mantle regime. Queen Salma offered a bounty for Greves the Overbearing, who met his doom in a fateful clash of steel and magic. Take up this famed quest once again and eliminate Greves to earn the royal bounty."
A popup of approx. 3 Wraiths and Smoke Phantoms is located just in front of Greves' group; these are native to the region and will be hostile to both you and the White Mantle. Triggering the popup and withdrawing quickly will leave them fighting Greves' group, offering you a tactical advantage.