So, the nerf on the Q and buff on the W...really nice. The idea behind those changes is good, Vayne is the ADC that does a lot of DPS damage with her W, especially against tanks, she is not made to do a lot of flat damage and oneshot carries with her autos empowered by the Q, that's Draven! xD
I dunno if is intended to make her Q proc 2 W stacks, but whathever...the idea behind the changes is good, and the rest is just numbers.
...the ult buff...WTF?!
First: Make no sense logic-wise, but ok, Anivia gets trapped by Cait so that's not SO important xD
Second: Is SO "avoidable", i mean, you nerf the big hits from the Q and you buff the W instead, that's just ok like this, why adding more stuff?! Just don't....
Third: if you really want to implement this thing, do it right, 20% of the enmy max health?! So if you are almost dead, and you las hit the enemy tank that maybe is running away with 100hp you gain 20% of his max healt (so like...70% of YOUR max health?! xD ) and you are back in the fight full health xD ven if you just autoed him once.
Suggestions: 1.The heal goes wiht your missing health, like dangerous game more or less, and maybe it scales with your AD or att speed, like 5% missing health plus 1% every X bonus AD or every X bonus att speed ( i suggested the att. speed even if it seems a bit strange, because i think the idea behind the changes is to make Vayne more about her W and this is gonna "enphasise" that)
2. it sclaes with the amount of damage you did at the enemy you killed?! Maybe...umm...i don't like this
3. It's just a flat amount instead of %, like the Kayn heal when he goes in to a wall with the E
If i made some grammar mistakes i'm sorry, i wrote it pretty fast.