Plains: Lox Armor that buffs blunt weapons while also giving the player resistance to blunt damage. Perhaps gives a % bonus to healing.

Would require Lox Trophy, Lox Hide and some wolf hide and needles (since wolves can hunt you in plains - it would be more of a trim for the armor).

Mistlands: Misthare Armor that buffs slashing type weapons (or weapons that involve slash), increases jump skill by a bunch and decreases stamina use by some sort of % like 15 or 20 (a general buff to offset Mistlands more difficult terrain).

Would require Misthare trophy, Misthare hides, Magecap and linen. Magecap could be used as a dye or give a part of the item some sort of glow maybe like the soles of the shoes or something.

I wouldn't want either type of armor to be super bound to the progression of each particular biome like involving Black Metal or Eitr. More like you could access either type of armor when you've already been dealing with the previous biome and simply spending the time to get the trophy / additional requirements. Both armors would require the workbench.

edit: Root Armor could be changed to buff pierce based weapons which would include bows and spears. It would also be nice if light armor could be upgraded somehow to keep in line with progression of the generic heavy armors.