The Garments of True King
by Not a DecepticonThis is not a unique item as much as a unique set of items that work together. I gave this list as a legend for Barbarian in my 5e campaign to collect, scattered around Known World.
The Garments of True King is a set of unique items worn by the First King of Beastmen, a legendary leader who united the Beastmen and ruled them with both power and wisdom, waging war against Nithians and upon his death Nithians have stolen them and hidden all across Mystara. The set consists of one item of different rarity each, with preexisting items Horn of Valhalla and Animated Shield fitting Rare and Very Rare spot and homebrewed item I've found, Farinyth, Malice of the Wolf as an artifact that is the final piece that can be only accessed when wearing other items.
Each item gets stronger with additional items of the set worn by the same person (eg. Horn of Valhalla changing to a stronger, rarer variant). two items completing the set are a Drunktard's Jug - a pin that lets you once per short rest gain benefits of drinking a potion of healing from drinking alcohol. I took that idea from a campaign I was in but added to it that with each item of the set it also can be used one more time and heals as a stronger potion.
The last item I homebrewed, using my friend's idea. It's Mantle of Leadership, which increases an ability to keep the troops' morale even in hard times. Here is how it works based on how many items of the set you have with you:
In itself, it is an Uncommon magic item that, when you are attuned to it you can cast Purify Food and Drink once a day and Goodberry once a week
With one other item it is Rare and lets you cast Purify Food and Drink twice a day, Goodberry once every 3 days and Create Food and Water once a week
With two items it is Very Rare and lets you cast Purify Food and Drink 3 times a day, Goodberry once a day, Create Food and Water once every 3 days, and Heroe’s Feast once a week
With three items it is Legendary and lets you cast Purify Food and Drink and Goodberry at will, Create Food and Water once a day and Heroes’ Feast every 3 days
With Whole set it allows you to cast Purify Food and Drink, Goodberry and Create Food and Water at will and Heroes’ Feast once a day
Inspired by my friend's idea. As she said, an army that is well-fed can keep their morale up.
Also, once someone collects the whole set, the races descendant of Beastmen (which in my game include Goblinoids, Orcs, Gnolls, Trolls, Kobolds but also Lupins, Minotaurs and Rakasta and possibly also Lizardfolk and Tortle) recognize the wearer as a figure of great might and authority. Lesser ones will flock to the wearer of the Garments as their leader, their leaders may be tempted to swear fealty to him and discouraged from opposing him, and even those of stronger wills shall recognize him as an authority. With this, the party Barbarian could, if she wished so, challenge King Thar for his throne or try to take over Renardy and be taken as a serious contender to the throne.