The vw is best used for tanking a mob with dots for himself.
If you send him to tank and throw SL, Curse of Agony, corr and maybe immo (depends on how much +damage you have). Like this he can just about keep aggroo, at least the levels just after you get the new versions of his taunt spell.
Don't do drain life now!
Find the next target, get max range and start dot'ing up while running and end with a fear. Throw in a lifetap or two if needed.
Send the vw after a 3rd target and cast sl on it.
The first target should be allmost dead now, so drain soul (I supose you have imp. ds).
Dot up the 3rd target, and return focus to target nr 2 and drain life and go drain soul when it's close to death. (should still be feared)
Take down the 3rd target or find a 4th to fear
and so on. You'll end up taking 4 mobs at the same time more or less, not getting hit and ending with full health and mana (if you get the imp drain soul to work).
This of cause requires the targets to be fearable,and if they are to close to each other and aggroo each other, you can expect to get nr 3 (and perhaps nr 4 and 5
) a little faster.
But dotting up only, and the vw can keep the aggroo
