Electrocute inconsitency

Since we are in pre season Ive been trying new build and there fore Im kind of perplex because I think electrocute Favor melee champs. Like lee sin only have to hit Q and re activate Q and instantly pop electrocute has you land resonating strike with AA (with is in 1 animation) same for kha zix press W and then in 1 animation you AA and Q pop instantly electrocute. While a champion like lux you hit E and AA prox illumination but it doesnt pop electrocute because the game seem to count has only 2 ability but there fore illumation is not a empower basic it say it consume the mark and it a third ability. Then I try out akali witch is a anoher champion that consume the mark and I had the same result, for akali I understant 1 Q and 1 AA missing the third ability. Next I went to try vayne with rageblade and get the same Result with the rageblade fully stack you hit twice 2AA+ W and it doesnt pop electrocute. That what I call inconsitency because I want to agree but it still 3 different ability.

Thanks you for your time