I think the vlad rework failed.
Based on experience from live, PBE, and video footage I can't help but think the rework failed.
Originally riot said they wanted to keep his identity when they announced his rework awhile back but I think destroyed it instead. From my perspective I always seen vlad as a short range AOE DPS mage with survivability in the form of his heavy sustain.
What i think they did to him is:
Destroyed his sustain.
Crushed his DPS in exchange for slightly higher damage on abilities.
Completely demolished his sustained fighting playstyle.
And finally handicapped his slightly higher damage with absurd %HP costs.
The balance between his Q and his E. Between the lower consistent sustain from his Q and the HP costs on his E it's impossible to mitigate the costs meaning you're always spending more than you're getting back in damage or HP. It's too unreliable and costly to make the ability at all worth using despite being his best source of damage.
His E is also an unreliable damage ability as it has a surprisingly short range and the ability acts as an explosion over an instant damage AOE. What this means is that it takes time for the damage to travel from you to the outer edge which makes it hard to chase with as the ability slows you as well giving them time to leave the circle before the damage and slow hits them. This ability also is crap in teamfights as this requires being able to get within a clear line of sight of people to use it but frontlines will be blocking them a majority of the time which basically cuts your teamfight damage in half.
Finally is that the HP costs actually discourage building HP now as his sustain is very limited but if you build more HP over raw damage you're increasing the costs more and more while your sustain is not able to keep as it is. If you get around 4k HP then your E cost at full charge will be around 400 but at the same time on your normal Q you might be healing 100 HP per cast at best, a small chunk more if it's the third Q.