Is Nanok's hero ability considered "armor" for armor effected elements of game play?

As far as I know, Armor is armor. Things that ignore armor include starting armor stats as well

As far as I know, Armor is Armor. Things that ignore armor include starting armor stats as well

Nanok's armor counts as armor for all purposes of gameplay. Just like the printed armor on a character sheet counts as armor.

I would consider things that affect the actual equipment piece (like CB for example) cant be used because there is no armor equipment piece there, but other effects that effect a characters Armor Value can (like pierce).

Nanok's ability affects his AV, and dictates that he cannot equip traditional armor. But its still 'armor' in the same sense that other characters have 'armor' from skills (parry etc) and equipped items (Chain mail).