Is there a trigger that changes the armor value?

What I am trying to do is keep a hero's armor value to zero.
The base stat will always be zero and will not gain any armor from agility so it shouldn't be too complicated.
Is there a trigger that modifies a hero's armor to 0?
If there isn't, is there any way I could do this?

If the armor will stay at what it starts with, just go to gameplay constants and find the constant that says base hero armor, change it to 0 instead of -2

Uh... That's not the problem...
I set it to zero and I made it so the armor will always stay at 0 excluding bonus from items. When I use Chaos based ability, the hero's item defence becomes the base defence.
I know how to change game constants... So please help me out with a trigger that will keep the hero's defence at 0. (excluding bonus from items)

Remove the item(s) giving the armor bonuses, apply chaos, then add them back.