Out of all the things I complain about, can we just remove it?
Its pretty toxic and uncounterable.
You counter %hp damage with armor/mr right? Wrong, true damage ignores armor/mr. So you counter true damage with hp, also wrong when its %max...
Riot, its like you don't understand why people are so bitter and toxic...
There are 2 champions with %hp true damage(unless you consider botrk+conqueror as such): Fiora and Vayne
Vayne's true damage is actually counterable(a bit) by getting an item with AS slow: 
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. And, unless you have a lot of armor and hp, her AA damage matters more than her W
Fiora's mobility allows her to dash through the fight to reach squishy targets, while her healing on ult requires her team to kill ulted target first, but she has to ult a tank to maximise her true damage potential. This makes it a difficult choice sometimes for the Fiora player. Without % true damage her only working tactic would be diving to enemy adc and ulting him.
Also, there is a reason for adding things like true damage/%armor pen/%hp damage. It is to make sure champion can deal well against tanks while not oneshotting everyone else. With just normal damage, to kill a tank with 200 armor and 4000 hp in 10 seconds, you need to have 1200 dps. Squishies with 2000 hp and 50 armor will die in 2 seconds to this kind of damage But if for some reason you could do 50% of your damage as true, you would need only 600 dps to kill the same tank in same time. With this damage you will kill squishies for almost twice as long. Looks much more balanced for me Same logic applies to other anti-tank stuff. It allows people to kill tanks in reasonable time without kiling non-tanks in unreasonably low time.
See this is where Id normally say it needs to be in the game to counter tanks from being too strong but.... almost everybody can deal with tanks right now
+1 If they keep it they need to lose their effectiveness vs squishies.
Til then, I permaban Vayne. At least Fiora's melee.
The problem is that the mechanics that can somewhat mitigate this are limited.
Abilities that cause Blind are rare, as are abilities that slow down someone's attack speed.
You are looking at it wrong.
As long as the numbers are low or there are fair requirements for getting the damage off, %hp true damage is fine. It basically puts a timer on a fight that the other guy has to win by. Inevitability isn't new in competitive games. The trick is making sure the other side has options to win now while the other one wants to prolong things as much as possible. As long as the other team has options to win first then %max HP true damage is totally balancable and viable for the game.
So if someone has a champ with %hp true damage, the first thing you need to be doing is figuring out how do you either blow that champ up as quickly as possible or how do you kill that champ outside of its threat range? If you are building HP or armor, your doing it wrong because that's exactly what the other guy wants out of you. If you are CCing it or bursting it down, that's a much better option.
the logic is that champs with % HP damage is that their kits are relatively weaker if they arent fighting champs with a lot of health.
%HP true damage means you do less damage to squishy targets, as in order to obtain similar damage to tanks you would need such an absurdly high damage that a squishy would take 2-3x as much.
It is balanced by its design, as it allows more damage to tanks while doing less overall to squishies.
You may not be able to lose less than 14% of your max health when damaged by something that deals 14% of your max health in true damage, but at least it's 14% rather than just one-shotting you.
