Itemization needs an overhaul

The theory of Percentage damage reduction, needs to be reworked. I've played this since S3 when mid laners ran Teleport, and the premier go to AP burst was Gragas with %Damage and %Mitigation.

The very concept of getting ahead by building 1 or 2 defense items against an opponent that just killed you, shoved your lane, and made you lose an entire cannon wave is absolutely horrendous.

Most of the time, when you see champion balances and tweaks, it's all in the interest of "balance and counterplay". With the current system in place, it's not good enough. We have cross item conceptualization with Ludens (thank god it's finally getting nerfed), and although ice boxed temporarily, the AP Funfire Abyssal scepter. My question is, for the likes of the Sunfire effect, why is this not true damage? The enemies flesh is melting off of their bodies. "Oh, my opponent built a Sunfire Cape, let me put on this null magic mantle and all is well"

Another scenario is the Thornmail. It is reflecting basic attacks, and as such, should NOT be an item that is mitigated by, yet again, putting on a fucking cloak. It should be true damage because the concept behind this item is to force auto attack reliant champions to either build faster attacks with smaller hits, or to build more defensively to withstand the reflect. Not, "reflects magic damage? Kaaaayyyyy, lemme completely mitigate the importance of that item by putting on a 500 gold cloak."

The damage reduction in this game is largely ignored to the extent that anyone can completely counter an opponent that has played their champion's kit well, even if you deny your opponent cs, experience, AND play safely.

Another thing, thornmail itself wouldn't be so useless, if you have either

1. Ignite
2. Morellomicon
3. A champion with Grievous wounds built into their kit.

OR as an alternative, bringing back Executioner's Calling, and making it a relevant AD item. Riot suggested it wanted to step away from the assassin meta, what better way to do so than through an assassin's sustainability?

Riot wanted to further expand on itemization within the meta ADC builds, by not nerfing the hell out of (semi) non-traditional ADC builds. (Blue Build Ez, Bruiser Urgot, Trispam Corki/Ez)

Why remove an item that is so integral to allowing champions to fight adcs?

TL:DR Sunfire Cape and Thornmail should deal true damage Bring back Executioner's calling Damage to Mitigation ratios are way off, highly in favor of Mitigation, Mitigation needs to be more expensive or Damage items need %Increase as an alternative