I'm gunna let you all in on a secret about fighting Vlad, specifically top.
Don't waste your money on
early.

ASAP gives you absolute lane dominance vs Vlad.
Due to Vlad's massive CDs and meager sustain early, Executioner's Calling does not accomplish much, and only delays more important items.
Hexdrinker removes all risk while all-inning, and mitigates the damage between all-ins as well.
Phage provides a huge amount of sticking power and engage potential in lane if utilized properly that will deal more 'effective damage' than the sustain that Executioner's Calling would remove.
Unless you can constantly proc its passive somehow without it being considered an all-in, Vlad will sustain almost as effectively as if you hadn't bought EC.
If you are going all-in, Hexdrinker removes risk, while Phage allows you to be more opportunistic with your engages, as well as chase him down the lane for a kill, thus is infinitely better than EC as well.
Yeah, I basically just said the same thing twice because I can't stress how much better hexdrinker+phage rush is than delaying your ability to do anything vs Vlad by building what's effectively a win-more item against him.
#Final tidbit that should convince you of why hex+phage is so much better:
Phage builds into both Trinity Force and Black Cleaver, which a large portion of top laners build anyway.
If you're not a champion that builds Trinity Force or Black Cleaver, you wouldn't buy EC either, and likely lose vs Vlad no matter what you do unless you're Rumble or something.
->

= Core on every mage
?
or
or any two of


are all more damage early game. 10% increased magic damage when your full combo only hits for ~800 or so is really not that great, so basically any item for the same price with more AP or an active is going to outdamage Abyssal early game.
one ttime top lane and he felt like that item didnt do anything for his lane.
it was in one of his youtube videos, i forgot which one
or something similar), he wins vs Swain.
Guaranteed lane dominance.
is better.
should not need a hexdrinker. It'd be be better to rush phage merc and then finish cleaver/tri force.