I tried to point out the idea of giving hazard immunity to Plate sets, but I was convinced that immunity to flinch would be better. So I changed the topic.
The following pieces of gear would receive:
-Plate Helm: Charge reset immunity
-Plate Armor: Flinch immunity
-Ancient Plate Helm: Charge reset immunity and Increased time of invincity frames (I guess... 2-3 seconds?)
-Ancient Plate Armor: Flinch immunity and Faster Shield Regeneration
I tried to keep part of my original idea on Ancient Plate, because it have MSD along with ASD. But Fangel came up with better ideas.
If it was implemented, problably we could call Ancient Plate Set as the ultimate tank set.
EDIT: I'm open to ideas.
A better excuse to make it "unstoppable" would be to make it 'immune' to flinching. Sure, the guy would still take damage, and get the ASD penalty, but now that his combos are unstoppable, it makes for a fair trade.
And... hazard immunity should only work for the Ancient Plate set. Because otherwise, nobody ever uses that set.