User blog comment:Simbey/Apophis, The Horror of the Sands/@comment-24242333-20131210093431/@comment-24242333-20131212125708

Well, in your first reply to this comment, you did say that the passive worked on the raw health gap, hence why I suggested stacking warmog and attack speed :)

You could, to save you some headaches and make it more true to it's name ("Horrific advantage") change it to a bonus when Apophis has higher % remaining health than his target.