sustain 
gg
Seriously though, one of Rumble's, Xerath's, and most AP champ's weaknesses were that because they were usually multi-target, they couldn't build Spell Vamp to sustain. Now you're basically asking for broken mages because like every mage ever will build this now.
annndd here comes the derp "33% effect" 1/3 effect mb luv <3
Sasogwa1 votesI doubt that. Xerath is too safe to need sustain, Amumu would rather have tankiness, and Rumble magicpen. Do not forget that it is still 33% for AOE spells. Vlad will become scary though, as he will be unkillable against tanks, his sustain not being reduced by their magic resist (his Q already has the healing part that ignores how tanky the guy is and that reinforces it). We'll see.
