Before engaging VanCleef, played had to defeat Captain Greenskin, who patrolled the area where VanCleef was standing. VanCleef initially had two level 19 - 20 Defias Blackguards. When VanCleef's health dropped below 50%, two additional level 19 - 20 blackguards would spawn. Some people said that ignoring the adds and just attacking VanCleef was the best tactic to kill him. Another method that worked was standing on the cannon to the left, just before you would step into the area Captain Greenskin patrolled. Then you'd get a mage on the cannon, and get a tank to draw VC and his adds out after killing Greenskin. You'd then draw them to the cannon, and get the mage to use some ranged attacks (a wand preferably) to distract the adds. The adds would *evade* the ranged attacks, but remain incapacitated until you'd stop. After killing VC, you could move onto the other mobs, one at a time.