New Tank Item That Takes Multiple Slots

The problem with good tank items is that bruisers will abuse them by buying one or two and then going AD, creating a very tanky champion who does a lot of damage too. I tank items were only good if they took up all your slots, bruisers couldn't buy them and AD.

New Item: Uses 4 slots regardless of upgrades (upgrades take slots, you keep one slot for boots and another for other utility) Grants health, armor, and magic resist based on the number of upgrades. Can be upgraded 3 times. The upgrades provide additional bonuses so that while you get stats from the upgraded item, upgrades let you specialize into a specific stat, along with passives like sunfire, warmogs, and frozen heart.

So a tank with little gold can realistically build this, components of an upgrade can be placed in reserved slots as well.