Thornmail should be Anti Crit item

Thornmail 100 armor unique: reflects 30% phys damage to enemies that attack you as magic damage excluding onhit effects unique: 15% critical damage reduction from attackers unique: Applies Grievous Wounds to enemies that attack you

So this item intention was to counter enemies that have huge basic attack damage aka Critical Strikes. However one problem is that Lifesteal is too much in this game making this item meaningless. On top of that Riot want ot counter on hit effect champions by adding armor scaling as damage reflection which steers away the concept of crit counter which Thornmail was suppose to be. Countering onhit effect champions with thornmail is absolutely ineffective. Not only that but this also reduces the effectiveness vs critical strike

20% lifesteal 15% lifesteal 10% lifesteal 10% lifesteal

Also adding 10% crit reduction to Randuin Omen is also kinda pointless since that wasn't the item purpose which was to reduce enemies Speed so i don't think removing crit from randuin is bad idea as the item originally was not made to deal with critical strikes but to give you general amount of protection and slow enemies

In order to counter Thormail you suppose to build magic resistance because it does magic damage. So who actually does that? All players do is build extra lifesteal and thornmail problems are over. GG Thornmail

Those items seems reasonable choice to counter thornmail . They provide both lifesteal and MR which you should be building to deal with This item does NOT provide MR but since it has 20% lifesteal so who cares?

And if we look at the word Thorn - you touch it, you bleed, you hurt yourself. Makes sense it should have Grievous Wounds