An exotic/unique that increases dodging would be pretty cool, but if we did get one then we'd also need a regular item that does it. You can't just say "Oh yeah active defense is a possibility on Nightmare! now that we have a 1 in 50 shot at getting the Ninja Garb"
Ninja GarbExotic ArmourDescription: A comfy, stealthy suit. It really is easier to dodge those fireballs with this on.
AC: 0
Durability: 100%, roughly the same 'HP' as blue armor
Move penalty: +5% (that is, you move a tad faster)
Special: Increases the chance of your sidesteps working by 10% (additive, so 50% becomes 60%)
Purple Armor (I guess 'Kevlar Jacket' or something would work?)
Regular ArmourDescription: This stuff is even less protective than your standard-issue equipment! Although, it does look good for getting around quickly.
AC: -1
Durability: 100%, roughly the same 'HP' as green armor.
Move penalty: +10%
Special: Increases the chance of your sidesteps working by 5%
White Armor (I don't know a good GRITTY REALISTIC TOTALLY NORMAL name for this one)
Regular ArmorDescription: The sides of the armor seem to deflect attacks. Perhaps that will make dodging easier?
AC: 1
Durability: 100%, roughly the same 'HP' as blue armor
Move penalty: -10%
Special: Increases the chance of your sidesteps working by 10%
JetpackUnique ArmourDescription: You've been trained not to run while shooting. They didn't say anything about flying, though.
AC: 0
Durability: Invincible
Move penalty: +30%
Special: Every time you do a non-movement action, you move in a random direction anyway. This forces you in to 'running mode' forever even if you're tired and unequiping it will make you tired.
EDIT: Added 'White Armor' to the post as a more midgamey alternative to 'Purple Armor'.