Emberglass Promise is a Demon Unique ring with no boss attached: it drops anywhere in Nightmare, most often from N10 up (rarer below that home difficulty, never above it), and nowhere else. Every copy is item level 100, and there 0.3% of what falls comes up Unique. It is built on Immaculate Ember Band — step 6 of the Ember Band line, item level 80 and up.

It always rolls the same numbers: +20 Power, +32 Power, +12% Power, +42% Fire Damage and +48% Burn Effect.

One Unique drop in 40 is a Mythical copy: the same item carrying 15–25% Mythical Energy that boosts every stat on it and can never be changed; the 15% floor is 10 times as common as the perfect 25%.

On top of that it carries Emberglass Promise — Your hits apply Burn; +10 Power.

It leans into Burn.

“Made in a forge that no longer exists, for a hand that never came back.”