have 685 HP before 
hit her auto attack.
's crit deal 581 damage. (no other damage is show)
die.
If you are wondering about this video's source, it from hi im gosu's stream hightlight: https://www.youtube.com/watch?v=k77-vy_9QBY at 1:39.
Mayor Stubbs1 votesShe has baron aggroe, my guess is baron hit her for the rest of the damage
Tranoze1 votes[{quoted}](name=Mayor Stubbs,realm=NA,application-id=LqLKtMpN,discussion-id=GElXLdtk,comment-id=0000,timestamp=2016-01-22T05:04:34.950+0000)
She has baron aggroe, my guess is baron hit her for the rest of the damage
Baron attack have animation too, and if you watch the video in 1:39 (original video) baron already attack lulu about 0.3 second (and take lulu HP away) before Vayne hit the auto attack. Baron deal 3 auto attack per second? no.
Mayor Stubbs1 votesBaron attack have animation too, and if you watch the video in 1:39 (original video) baron already attack lulu about 0.3 second (and take lulu HP away) before Vayne hit the auto attack. Baron deal 3 auto attack per second? no.
I know baron has a lot of different abilities that deal damage than just his AA, I don't have enough knowledge to tell you what the rest of them are but I know I take more damage standing near baron than just from his AA.
I'm not 100% certain this is what caused it, but i'd say it's more likely baron damage than Vayne dealing more damage than it's showing from the text.