The job of a tank is to soak damage and maybe cc. That's about it. Why is there a class that would negate that? IF there was TRUE balance then the tank would be "unkillable" but in turn do terrible amounts of damage. The whole point is not to focus the tank right? In this case one person (vayne) is a tank killer who wants to focus the tank/ doesn't mind.
IcyPepper3 votesADC's in general take down tanks late-game, contrary to popular belief is that the ADC can focus the tank in a teamfight as long as they are safe to do so. Since tanks tend to be on the frontline, they tend to be the first target of the ADC since they're the only ones within "safe" range of their aa. If the ADC tried to attack the backline without support, they would get cc'd by a mage or enemy support and be killed by a burst mage or assassin.
The point of the ADC destroying the tank in a teamfight is to remove the enemy team's safety and peel. Without a frontline, your burst can focus the adc (removing the enemy team's sustained damage), your tank can dive the enemy burst while you destroy them with your support protecting you.
Tanks want to be focused, making them too easy to ignore would remove the incentive to. They're not just cc bots, so they get a little bit of base damage. ADC's, on the other hand, have the tools available (LW, BORK and BORK is a bit stronger than Liandries when it comes to tank busting) to focus them properly. The key to teamfights is focusing priority targets for your role (wasting all your rotations as Zed on the enemy tank isn't as effective, but sometimes necessary. Priorities shift too!), protecting the ADC so they can destroy the enemy's tank, and positioning yourself so you're either soaking up damage (as a tank/bruiser) or dealing damage without taking as much (mage/ADC).
Vayne is the premier tank buster. Giving her that %hp true damage is like giving Irelia flat true damage, Vayne busts tanks even faster and Irelia bursts squishies even faster. Is it healthy for their roles? Debatable. But the idea of a tank buster isn't bad design, at least imo.
DrNova2 votesKog can shred tanks as well, but he is nowhere near as safe.
There are few true tanks in league, maybe a couple sup's, but all the other tanks are realty just bruisers.
franticFurball1 votesActually, if played right, and with a team that knows how to unlock his power, Kog is even safer than Vayne, because he shreds from a safe distance with his Bio-Arcane-Barrage (or whatever its called) active.
DrNova1 votesHe can be, but you really need a team smart enough to peel, cause kog is squishy and has no extra mobility. But yeah if you have that he's a beast
Mecha MaIphite1 votesFor me it's how slippery she is. Her E, Q, and invisibility is the reason she can 1v1 so many strong duelists. She can even 1v1 a lot of assassins who's burst combos take too long to execute.
BeatRushVII1 votesThere are other tank shredders,but they see less play than vayne because vaynes kit provides the same service with more safety built in for the most part.
I really do like the idea of vayne , but her kit is just problematic to balance and still keep what makes vayne vayne.
Big Lincoln1 votesi don't think being able to assassinate a tank is a well-thought concept
even if you're a champ who "specializes" in killing them (Even though Vayne is just a universal assassin and not a tankbuster) you shouldn't get a free pass to shred them like they're squishy. that just feels bad to play against
HEAljvLykd1 votesChange vaynes w from max hp to current hp and problem solved.
Enosetc1 votesthe problem with vayne is that she skews duels against tanks so heavily in her favor that it's almost to the point where individual skill doesn't matter. condemn + tumble is enough to keep you away from most tanks without them ever having to worry about them being able to fight back. she hard counters tanks in the same way pink wards hard counter akali in teamfights and it makes playing a tank against her feel absolutely awful.
Only Play Darius1 votesProblem with Vayne is she isn't an exclusive tank killer. She is also a squishy melter assassin, an invincible duelist since she has a dash and a knockback to maintain an uncounterable range advantage, and late game monster through high mobility, that true damage you can't build against is just an added bonus.
If you want to see a real, balanceable tank killer look at 
SwapShadows1 votesthis would make sense if most tanks in the game didnt deal absurd amount of damage while being tanky.
KitsuneKrash1 votesHonestly the biggest problem with Vayne is that it's % hp true damage. Both & 
have % hp magic damage, which deals with tanks just fine despite being able to counter build to defend yourself. Making Vayne deal % hp physical still would allow her to deal with tanks, but not be so overly oppressive.
The only other option would be to somehow remove her synergy with BotRK, which I have no idea how to go about doing so. Least not in a way that doesn't punish other champs.
