Buff Doran's Shield
Mid laners have access to Doran's ring. A wonderful item for extra mana regen and some early health. Adcs have Doran's blade to help sustain by aaing lane and outpoking opponent's.
Tanks currently are stuck with shield, which gives a small amount of flat health and small regen over time. It is the only Doran's item that is gold unefficient and many top laners prefer dorans ring or blade to the shield.
My proposed change would be lowering the cost to 400 to start off allowing a 2 health pot start and a slight buff in the health regen passive of the item. I don't see the unique passive needing a change as the niche of the item is more placed into health and regen then basic attack reduction.