Hybrid Pen Item

So we have Last Whisper for Armor pen and Void Staff for Magic pen, but what about a hybrid pen item?

When I play people with AP scalings on an ability that does AD damage, it feels really weird to build LW. Like when I play AP MF, about half her damage is AP and half her damage is AD (the AD damage scales off AP and the AP damage scales off AD...)

I realize there are very few champions who are hybrid carries (Jax, old Akali) but I would really like to see an item like this. Obviously it wouldn't give the full +35% pen for both but maybe something like 20-25% would be better.

We already have the weird mastery that gives +6% armor pen and magic pen, why not make an item to amplify it?