[2019] All damage is converted into true damage. Who becomes the best champion? Who becomes the worst?

If all damage converted into (or just was) true damage, who would benefit the most from that? Just a shower thought I had, and I'm sure you smart people can tell me the optimal champs to play in that kind of meta.

My vote is on Cassiopeia, that sounds disgusting with all her very high scaling and dps.

Other champions that have really high scaling or base damage would be good too.

For worst champions I would probally have to go with Yummi, and basically every tank.