Skeletal Armor

Armor (studded leather or hide), rare

This armor is covered in hardened bones and skeletal fragments. You can use a bonus action while wearing this armor to transform its skeletal remains into a skeleton that's one size larger than you (a minimum of Large) for 1 minute; you remain inside the skeleton's chest cavity for the duration. You then gain 1d10 + 20 temporary hit points: the effect ends early if you no longer have these temporary hit points, if you're no longer within the chest cavity, or if you end the effect using a bonus action. When the effect ends, any remaining temporary hit points are lost, and the skeleton reforms around the armor as you land in an unoccupied space within 5 feet of it. If the effect ends early as a result of you losing these temporary hit points, you must also succeed on a DC 10 Dexterity saving throw or fall prone.

While within the skeleton's chest cavity, you control it like an extension of your normal form (your AC and other statistics remain the same). When the armor transforms, you can choose to have it wield any weapon you're holding; any weapon it's wielding drops to the ground at your feet when the armor returns to its normal form. The skeleton otherwise carries no weapons. For the duration, your reach with your melee attacks as the skeleton increases by 5 feet, and if you move at least 20 feet straight toward a target and then hit it with a melee attack on the same turn, the target must also succeed on a DC 15 Strength saving throw or be knocked prone.

Once the armor transforms, it can't do so again until the next dawn.

These bones lived, once.
That does not mean they no longer yearn. Listen to them: hear the echoes of their passion and become their beating heart. Do so, and they will have the chance to—for a moment, at least—live on.
As will you.