For all the talk about how you are supposed to "Outplay" percent true damage...
It feels like there really isnt any outplay allowed. Out of the various sources of %true damage, you have
Silver bolts, in which one of the highest AS and most AS focused champs in the game only have to hit you three times to access it, not to mention her auto reset and incredible chasing. You have
Vitals, in which her passive is alright if RNG doesn't choose to put them right in front of her, but when she presses R she gets free MS just for walking around in the zone, an unbeliveably short cd dash that can proc them, along with two very potent slows allowing her to hit the four with ease. And finally we have
Villain Mechanic, which is applied to a player for doing well. In which his damaging abilities and auto attacks do true damage to their target. (Note: Only the ult does full True, the rest just do 1% per tic of damage). Out of the three champs listed with this mechanic, really, the closest one who has outplay built in is
because he has no choice in his target, and as a Juggernaugt, no real way of getting to and sticking on his Villain. I just feel like whether you think the kits are balanced or not, Riot has failed in actually granting % True damage as a mechanic any real outplay. There is no skillshot, no long cds, and no real items that can help counterbalance it, short of the niche Frozen Heart for 
TL;DR: % True Damge as a mechanic you are supposed to outplay is not really outplayable at all.

orb also does true damage on its return back to ahri
passive and one of his ultimate upgrades from does true damage
reckless swing does true damage
death passive does true damage
and even
does true damage with her bite if you are at max fury when u use it