Hellflame is an extremely powerful Quirk that gives Enji pyrokinetic abilities.
Enji is able to generate large fire blasts to incinerate his opponents, as well as cover his body in flames. Changing the temperature of the flames is possible as well, which means that their damage output is capable of increasing or decreasing depending of Enji's wishes. The anime adaptation shows that those flames can heat up to the point of turning blue.
Hellflame will raise Enji's body temperature to dangerous levels if overused due to successive powerful attacks or drawn-out battles, impairing his physical abilities.
Enji likes to keep his body in a flaming state, in order to look more imposing as the Flame Hero Endeavor.
Endeavor fights by using his flames to overwhelm his opponents with extreme heat. His attacks include large-scale flamethrowers, precise heat-rays, and fists of fire among other options.
Endeavor uses low-temperature flames on weaker opponents to be used as a warning shot that normally incapacitates Endeavor's targets, or to minimize the strain on his body. The Flame Hero raises the heat whenever he's trying to finish off the opponent; high-temperature attacks are meant to defeat foes definitively, as they raise Enji's body temperature significantly. This is a high-risk tactic that can backfire if he uses too many of these techniques.
Hellflame can also be used to prevent Endeavor from falling or suspend the Flame Hero in mid-air by expelling fire jets through the soles of his feet. He can also eject flames from his back to propel himself forward. This same ability can be used as a reverse thrust should Endeavor need to resist an attack.
Endeavor's signature move is called "Flashfire". It raises his flames to their maximum temperature to create a powerful heat-ray that vaporizes any target. The heat from this attack raises Enji's body temperature to its limit and immediately impairs his abilities going forward.
The anime shows more combat applications for Hellflame. Endeavor can shape his flames to function like various weapons and is able to heat up the soles of his feet to anchor himself to walls through molten footprints, allowing him to run along their surface. Burning down a target at a cellular level is possible for him as well, letting him bypass healing or regenerative Quirks with flames of extreme temperatures.
- Flashfire Fist (赫灼熱拳 Kaku Shakunekken?): Endeavor's signature technique, he raises his fire's temperature to its highest level and maximizes his power. Doing so, the Flame Hero can unleash devastating flame attacks or increase his speed dramatically.
- Flashfire Fist - Jet Burn (赫灼熱拳 ジェットバーン Kaku Shakunetsu-ken Jettobān?): Enji shoots flames out the back of his fist to propel it forward and delivers a powerful blow to the enemy. This was first seen used against Hood.
- Flashfire Fist - Hell Spider (赫灼熱拳 ヘルスパイダー Kaku Shakunetsu-ken Herusupaidā?): Enji shoots streams of fire out of his fingers to burn his enemy. The flames take a form similar to a spider's web, hence the name. The flames are hot enough to burn through Hood's muscles and dice a building apart.
- Flashfire Fist - Hell's Curtain (ヘル カーテイン Heru Kātein?): Enji throws both of his fists back while concentrating all of his flames into a single point. He then throws his arms forward, throwing a massive blanket of flames on to his opponent.
- Karmic Raze - Hellfire Storm (
業火 燎原ヘルファイアストーム Gōka Ryōgen Herufaiasutōmu?): This attack allows Endeavor to create a powerful flaming whirlwind that burns opponents within its range.
- Raging Assault - Hell Minefield: This attack allows Endeavor to erupt a wave of intense flames across the ground.
- Vanishing Fist (バニシングフィスト Banishingu Fisuto?): Endeavor rushes towards his opponent while engulfing his arm in flames before delivering a powerful hook punch. This technique was first used against Tomura Shigaraki in the Paranormal Liberation War Arc.
- Prominence Burn (プロミネンスバーン Purominensu Bān?): Enji burns brightly and intensely before shooting out a beam of highly pressurized flames. This attack is strong enough to overwhelm Hood's Super Regeneration and to incinerate it. However, the creature survives by tearing off its own head.