Permafrost Platearmor(half plate, plate), very rare (requires attunement)

This pale armor is frigid to the touch, and even in the warmest weather has a thin layer of frost over it. The wearer must endure wearing the cold plate for an entire hour to attune to it. You have a +1 bonus to AC while wearing this armor. Additionally, you have resistance to cold damage, and are unaffected by temperatures as low as -40. A chilly draft follows you wherever you go and while you are conscious any hostile creature that ends their turn within 5 feet of you takes 1d10 cold damage.

half plate, plate
very rare