I'm trying to figure out if spell vamp procs off of things like 
's W. blighted Quiver. Basic attacks deal bonus magic damage. Or on the item 
. Basic attacks deal bonus magic damage. I'm beginning to think that is does not but I'm just making sure. Although it does seem like it should since your dealing magic damage.
Thanks in advance.
spell vamp doesn't care if the damage is magical or physical it affects damage dealt by abilities no matter the damage type (also works on true damage, nunu gets a bigger boost to his consume heal from spell vamp than from AP) physical damage lee sin kick? spell vamp works, magical damage annie disintegrate? spell vamp works, gunblade active? THAT'S AN ITEM NOT AN ABILITY NO SPELLVAMP although it generally gets a little fuzzy when it comes to abilities that add on-hit damage. i think actives that provide temporary on-hits work, toggles like cho'gath's work, but full blown passives like varus's do not, and there are always exceptions somewhere.
wiki is your friend
http://leagueoflegends.wikia.com/wiki/Varus
looks like it does not: usually spellvamp is applied to spells ( aka abilities, not magic damage ) so it needs to be cast on a skill most times; W is a proc on hit and so is the damage, so rule of thumb does not want it proc.
Thanks for clearing that up for me.
