20% chance to defend with 200% armour?

Defend

Testing: Let a monster attack me over and over. Check defense tab to see the result.

After getting hit hundreds of times I never saw the defense change on my defense tab. I thought then that it might be when I hit? Still no difference registered on the defense tab. Thinking that it may trigger off a guard skill, I cast Molten Shell over and over only ever seeing the new result from MS's armour buff.

Assumption: New defense result from defend does not register on the defense tab.

Consecrated Ground

Testing: Let a monster attack me until it gets a critical strike proc'ing Commandment of Light Labyrinth enchant on gloves.

Does consecrated ground do anything to monsters? I read that it no longer grants a critical strike bonus unless generated from Bottled Faith, but does it do anything like a degen effect to monsters? Also I saw when it proc'd that my arc from Mjolnir would proc and also the buff from Herald of Thunder. Is this intended?

Can someone please clarify this? Also, I cannot see a duration for defend either. I have exhausted every avenue via google and this my only hope.

Thank you!