A reasonable to balance around Lucian etc. Black Cleaver build

We all know the new black cleaver was made for bruisers and are essential to Darius and Garen, who have a physical damage DOT to stack up black cleaver real quick and deal hella damage in no time into the fight. Now MF and Lucian pick up black cleaver for dem decent raw stats and smooth build path. Plus they can also utilize black cleaver's passive super fast with their kits, MF can AOE shred armor with ult, Lucian is even more ridiculous, Q into passive is an instant 3 stack, he can also stack 5 times with ult (which is why now Cullings hurt like a motherfucker)

Anyways, it is reasonable to nerf this part of black cleaver to limit the power of ADC's use on black cleaver instead of lowering its stats or giving it a weird build path, or we will destroy those who are supposed to use them. My suggestion is to give Black Cleaver's passive an super small internal coodown that works good with the tick rate of Darius, Garen, Wukong etc. but not so well with Lucian who can stack up super fast In the end, it's not Lucian being broken at the moment, it's this specific build boosting his gameplay to another level. And we should try to limit his use on Black Cleaver instead of plain nerfing Lucian's kit and/or Black cleaver itself.