Sion W needs fix

The wording on Sion's w is "gains health whenever he kills a unit", however it does not give health when killing zz rot creep, malzahar's minions, zyra's plants, and others of the sort. Either it should give him health or the wording should be changed. But I am in the belief that it should give him health due yo nasus and veigar being able to farm zz rot for stacks, so Sion should be able to as well.