This idea is AD-armor item that benefits skirmishers, fighters, tanks, and is focused on late game defensive scaling as well as long term endurance on the battlefield.

The item benefits both auto attack based champion as well as those who rely on their abilities. Instead being focused on its offensive part, its focused on endurance and it rewards for stacking armor.

Originally, the intent of the items was based on melee auto attack champions that requires them to stick to their targets for longer period of time. Since they are in very close range they will get focused easily so some defense option would be a good idea. Such champions are Master YiSquare Master Yi, Xin ZhaoSquare Xin Zhao, OlafSquare Olaf, TryndamereSquare Tryndamere, and many others. These warriors require them to stick to their targets for extended period putting themselves in direct danger. Item like that would reduce that vulnerability but the item is mainly focused on defensive stats rather than offensive so it does require extra armor to work better for late game.

As the concept is based on auto attackers I figured out that there would be wider variety of champions that also relies on their abilities and are champions that scale with armor, such as
ViSquare Vi, WukongSquare Wukong, Jarvan IVSquare Jarvan IV, and so on.

There are also the tanks who might not care about the offensive stats that much but are focused on durability, for example RenektonSquare Renekton, PoppySquare Poppy, GarenSquare Garen.
They might not care about attack speed but other stats are welcome for them especially if they wanna scale against AD opponents and require them to stack armor.

Other possibilities: MalphiteSquare Malphite, RammusSquare Rammus. Those champions primary scale with armor so I think there is a chance that this item would benefit them even if it gives AD instead AP but still it scales with armor non the less and they will stack tons of armor.