Like his father's Quirk, Hellflame, Blueflame grants Dabi fire-based abilities, particularly creating and generating fire from his body at will. However, unlike Hellflame, Dabi's are blue in color meaning that they burn much hotter.
The user can ignite blue fire anywhere on their body with minimal effort or movement almost instantaneously. They can also combust anything they touch almost instantly, including robust minerals and living creatures alike. For example, by touching a single tree in The Beast's Forest, Dabi was able to set the majority of the forest ablaze, trapping everyone there in a ring of fire.
The flames of this Quirk are extremely hot, burning at a temperature of at least 2,000°C (3,632°F), which is higher than that of lava and normal fire, signified by its blue coloration. Dabi's flames were hot enough to burn an entire group of villains into ash in mere seconds. They're also quite bright, making them effective against Dark Shadow.
His flames are powered by his hatred and rage, so the greater his anger, the hotter his flames are.
The major drawback of Dabi's ability is that his body can't handle the heat due to inheriting his mother's genes which grant resistance to freezing temperatures instead of intense heat. Overusing his flames will cause his skin to swell, sizzle, and slowly burn over time. This prevents Dabi from fighting prolonged battles and severely limits his endurance. As stated by Dabi upon overusing his Quirk, prolonged usage of it causes him to lose sensation in his body and possibly render himself completely numb. Losing control of his emotions will cause his flames to run wild or ignite hotter than his body can handle.
During the second war, the danger of this weakness has become more apparent as Dabi continues to abuse his Quirk. This has led to his already burned flesh beginning to crisp away and fall off, effectively destroying his body.
Dabi primarily uses his Quirk to fight from a distance and burn his enemies using waves of fire and flamethrowers. He can also release a short burst of flames for roasting his targets at close range. Dabi often relies on the brute force of his powerful Quirk to overwhelm his enemies. His fire blasts are powerful enough to collapse building walls and were enough to completely repel Snatch's Quirk.
Dabi also uses his Quirk tactically, creating walls of fire to trap his targets within a fixed area or to propel himself in midair through the soles of his feet. This Quirk also combos well with Compress, as anyone compressed along with some of Dabi's flames will burn to death.
Because Dabi's flames tend to weaken his body with prolonged use, he is unable to release successive attacks for long. To counter this, he will often engage in rattling the enemy in order to buy himself some cooldown time. Additionally, Dabi has learned to take some heat off his attacks in order to reserve more power for himself for critical situations.
- The flames of Dabi's Quirk used to be red, and turned blue when Dabi hit puberty. This implies that "Blueflame" is the current designation of the Quirk's name, and that it was referred to as something else prior to becoming blue.