Band of Immolation

Sentience. The Band of Immolation is a sentient chaotic evil item with an Intelligence of 15, a Wisdom of 12, and a Charisma of 18. The ring communicates by transmitting emotion to the creature carrying or wielding it, and it has hearing and normal vision out to a range of 60 feet. The ring craves destruction, and it likes inflicting indiscriminate harm on others. 

Nondetection. The Ring of Immolation defies attempts to magically locate it. Neither the ring nor its wearer can be targeted by any divination magic or perceived through magical scrying sensors.

Everlasting Flame. As long as you wear the ring, you don't age naturally. This effect is similar to suspended animation, in that your age doesn't catch up to you once the ring is removed. The ring doesn't protect its wearer from magical or supernatural aging effects, such as the Horrifying Visage of a ghost.

Fire Immunity. While attuned to and wearing the ring, you have immunity to fire damage and don't suffer any ill effects from extreme heat.

Magic. The Band of Immloation has 12 charges and regains all its expended charges daily at dawn. While wearing the ring, you can expend the necessary number of charges to activate one of the following properties:

• You can expend 1 charge as an action and use the ring to raise the temperature in a 120-foot-radius sphere centered on a point you can see within 300 feet of you. The temperature in that area rises 50 degrees per minute, to a maximum of 1,000 degrees Fahrenheit. objects begin to ignite into flame and surfaces become charred and blackened once the temperature rises above 424 degrees. This effect is permanent unless you use the ring to end it as an action, at which point the temperature in the area returns to normal at a rate of 10 degrees per minute.
• You can cast one of the following spells from the ring (spell save DC 17) by expending the necessary number of charges: Arcane Hand (2 charges; the hand is made of fire, is immune to fire damage, and deals radiant damage instead of force damage as a clenched fist), Cone of Cold (2 charges, fire damage), flesh to obsidian (3 charges; as Flesh to Stone except that the target turns to obsidian with the density and durability of stone), Fire Shield (2 charges), Fire Storm (3 charges), Fireball (1 charge), Hellish Rebuke (1 charge), or Wall of Fire (2 charges).
• You can expend the necessary number of charges as an action and use the ring to create either an inanimate magma object (2 charges) or an animated magma creature (4 charges). The obsidian object can't have any moving parts, must be able to fit inside a 10-foot cube, and has the density and durability of metal or stone (your choice). The magma creature must be modeled after a beast with a challenge rating of 2 or less. The ice creature has the same statistics as the beast it models, with the following changes: the creature is a construct with vulnerability to cold damage, immunity to fire and poison damage, and immunity to the following conditions: charmed, exhaustion, frightened, paralyzed, petrified, and poisoned. The magma creature obeys only its creator's commands. The magma object or creature appears in an unoccupied space within 60 feet of you. It hardens into obsidian after 24 hours or when it drops to 0 hit points. In extreme cold, it loses 5 (1d10) hit points per minute as it hardens.

Other Properties. 

The Band of Immolation is rumored to possess other properties that can be activated only by an evil being whose will the ring can't break. Fire giants have long believed that the ring can be used to immolate entire worlds, while an efreeti in the service of an ancient red dragon once claimed that the ring could be used to summon and control red dragons, as well as the mighty fire primordial named Imix.

Destroying the Ring. 

The ring is nigh indestructible, resisting even the most intense magical cold. If it is placed within the maw of the powerful primordial known as the Cryonax, the ring freezes and is destroyed forever.