Please don't screw up black cleaver! Just make a whole new item!

Riot is pretty picky about keeping a cap on any excess items. I for one think there's room / legitimate reason for both to coexist.

Somewhat irrelevant to op but I'll just say this here. I'd also like to see another 15% CDR item. I think it would work nicely on it. With 450hp or 45 ad and 15% CDR. I don't need that much CDR on xin Zhao for example since my autos reduce my spell cool down. There are already a couple CDR bruiser items to pick from too

If they made the new black cleaver into it's own item just to keep the old black cleaver I'd never touch the old one again.