League of Legends (LoL) Question: Is Armor penetration on Volibear a viable option?

If we're looking at Top Lane Volibear, AD marks are likely better for general trading. The only champions that really make use of ArPen runes have either built in AD steroids like Zed, Riven and Trundle or have very reliable armor sheds innately to further abuse the enemies lack of armor like Jarvan IV.

I am however unsure on Quints. I'd assume you'd run AD quints as well, but could see AS or Movement speed quints, or even armor quints with flat health seals.

As for your concerns that his abilities do not scale with AD, it's really not about the scaling, and more about general offense. Volibear does have to auto attack to do what he does (good ol' fashioned maulin'.), and in doing so, Flat AD will probably get the job done better than ArPen. I'm like 90% sure on that. You'll need a mathcrafter for like, conclusive ****.

No

Are you playing him in top lane or jungle? I tend to think attack speed runes are better suited to jungling. Armor pen could work in top lane but you would probably want to build a bit of early AD to make it worthwhile outside your W.

it depends on the way your playing him, i play him as a jungle tank with 5000+ health that my frenzy is doing enough damage to take down a few daruis in less than a few seconds without armor pen. The choice is mostly on what their team is, i prefer the health and armor more or less but bruiser volibear can be a terror top lane.