A Sky Flame is one of the type of flames in the Dying Will Flames of the Sky. Sky Flames are the most comparable to actual flames, as it can burn objects and release heat. Bearers of the Sky Flame are said to be exceptionally rare, and most of the known ones commonly possess great insight.
Sky Flames are colored mostly orange in its core with yellow-orange to bright yellow outlines. It also flickers like fire. Two different types of Sky Flames are known to exist. First is the "Soft" Sky Flame, the normal type that Sky Flame users can produce. The concentration of its energy dispersed, so it is suitable for hovering or maintaining a stance. The soft Sky Flames have an orange core with pale orange to bright yellow-orange body.
The second type is the "Hard" Sky Flames. They are said to have the highest purity among the other types. They are released by an increase in explosive energy and are used for a straight burst of speed or simply raw power. Its core has a reddish shade of orange and the parts closer to its edges are colored by varying shades of orange with sparkling crystal-like particles.
Described as having many mysteries, its characteristic, Harmony, represents a state without contradiction nor flaws in which the balance of the whole is maintained. The Harmony characteristic allows it to combine with other type of Dying Will Flames to create a new one. The Oath Flame is a combination of Sky and Earth Flame. The Flame of Wrath is hinted as a fusion of Sky and Storm Flames due to Bester's Sky/Storm Liger Mode. Tsuna's Zero Point Breakthrough: Revised utilizes the Harmony characteristic, as it "harmonizes" with the enemy's Flame and absorbs it.
In addition to Sky-attribute Box Weapons, Sky Flame users are also able to open Boxes of all attributes. However, it cannot draw out their full potential.
- Most canon characters that occupy or are aspirants for the position of mafia boss possess a Sky Flame.
- Ironically, despite being described as rare, about 20 named characters have been revealed as bearers of Sky-attribute Flames, which is more than any other attribute have individually. However, it must be noted that most of the 20 said characters are already deceased.