My Proposal to Bring Back Flat Armor Items: The Helmet of Lokfar
I think that the biggest problem with items like Frozen Heart and Thornmail is that they are so eclipsed by items like Randuin's Omen and Sunfire Cape due to their Health bonuses. These bonuses are quite large, and against true damage champions such as Vayne and Irelia they're invaluable. The final nail in the coffin for the healthless armor items is the armor penetration items, specifically Last Whisper, which makes them borderline useless on even the most mana hungry champions. This new item I'm proposing will give a little bit of health for the healthless armor items.
Helm of Lokfar
Build path:
+
+ 1337 gold
250 health
250 mana
30 Armor
50 Magic Resistance
10% Cooldown reduction
Unique Passive: Every point of armor grants +2 bonus health. Every point of magic resistance grants +2 mana. The health bonus is halved on items with health bonuses already in place.