I've made a homebrew magic item (Based off of a LOTR ring if you know it). Does it looked balanced, should I change the rarity to artifact, or are there any features I should add?

  Narya, the Ring of Fire

Please, can anyone help me? Constructive criticism and tips are welcome.

Quote from The_Lightless_One >>

I've made a homebrew magic item (Based off of a LOTR ring if you know it). Does it looked balanced, should I change the rarity to artifact, or are there any features I should add?

  Narya, the Ring of Fire

  

Ring, legendary (requires attunement)

 

While wearing this ruby studded ring of pure gold, you have resistance to fire damage. While this ring is worn, it is invisible to all but its wielder and the bearer of another ring of power. In addition, while attuned to this ring, you gain the following benefits: 

Immortality. While wearing this ring, you do not age, and cannot be aged by magical effects.

Spark of Hope. While wearing this, you are immune to the frightened. In addition, you can use an action to give any creatures of your choice within a radius of 30 feet advantage on saving throws against being frightened. This effect lasts until the start of your next turn. 

Scrying Shield. While wearing this ring, you cannot be targeted by any divination spells unless you want to.

Ring of Power. Narya cannot be destroyed by physical or magical means. If the One Ring is destroyed, Narya loses all its powers and becomes a nonmagical ring.

Looks pretty good, it is a legendary ring, I would even call it a minor artifact if you wanted.  I would suggest a couple of tweaks.

• Perhaps give the wearer the ability to understand Deep Speech or some other weird language of its creator, not speak it, just understand it.
• Spark of Hope-  I would change this from action to reaction or bonus action since it only lasts 1 turn,  if changed, limit to once per short rest or 3 times daily.
• Ring of Power-  Most magical items are already very difficult to destroy, is there a Lore reason for listing how the ring is to be destroyed?  Perhaps add a minor corruption to the ring over continued use since it is so powerful and would fit the theme.  Also, the player should only know how to destroy the item after intense research or magic, say through a Legend Lore spell or a Divine Intervention, or high DC History/Investigation checks in a certain library.  This is something both the ring and the creator will want to stay a secret.

I'm not sure how many rings you want to come up with overall.  You could reduce the powers some, create three different rings then have greater powers when all 3 are collected by one person, that could be a minor corruption too, they have an intense drive and unbearable greed for finding and possessing the other rings and combine them into a single powerful artifact ring. 

This is just spit-balling, I tend to favor minor useful items being upgraded into fantastical items over the course of a campaign, it usually drives the player to become more interested and engaged with the Lore and the Setting, a goal beyond just killing stuff for XP and gold. Just adjust the power of the ring and modify it as you see it used in gameplay, the best way to discover how to abuse an item you made is to give it to a player.

Thanks very much! To answer your question, the terms of destruction are tied into the lore, and they are why I was considering making it an artifact.

I added another feature, and changed Spark of Hope based on your recommendations:

Elven Forged. You can understand spoken and written elvish, but cannot speak it unless you could before attuning to this ring.

Spark of Hope. While wearing this ring, you are immune to the frightened condition. In addition, you can use your bonus action to give any creatures of your choice within a radius of 30 feet advantage on saving throws against being frightened for 1 minute. Once you use the ring in this way, you cannot do so again until you complete a short or long rest.