Nightstalker's Armor of the Northeastern Wind

This unusual armor is composed of blue metal plates with a horned helm, and was tempered by the frigid breath of an oni.

Retributive Cold: When you take damage from a creature that is within 5 feet of you while wearing this armor, you can use your reaction to deal 1d6 cold damage to that creature.

Freezing Fog: While wearing this armor, you can use a bonus action to speak its command word to cast the gaseous form spell from it, targeting only yourself, with the following changes:

• You take the form of a frigid cloud of fog, creating illusory frost on objects you touch.
• You can take the Attack action while in this form. When you do, your attacks are unarmed strikes that deal 1d6 cold damage, instead of their normal damage.
• You can use the armor's Retributive Cold property.
• The spell has a duration of 1 minute.
• Once this property has been used, it can't be used again until the next dusk.

Plate consists of shaped, interlocking metal plates to cover the entire body. A suit of plate includes gauntlets, heavy leather boots, a visored helmet, and thick layers of padding underneath the armor. Buckles and straps distribute the weight over the body.

The wearer has disadvantage on Stealth (Dexterity) checks.

If the wearer has a Strength score lower than 15, their speed is reduced by 10 feet.