Recently, it was revealed that Fire Force, an anime about a group of pyrokinetic firefighters, is getting a third season (via HITC). Outside of this series, there are lots of creative uses of fire in that anime that create mind-boggling animation. Of course, there are plenty of other great fire users in anime.
These characters are just as passionate as the flames they use in fighting. Fire is a dangerous tool, but these characters are able to wield it at no risk to themselves. This makes these the cream of the crop when it comes to pyrokinetic anime characters.
Natsu Dragneel (Fairy Tail)
Natsu is one of the two protagonists of Fairy Tail, alongside his partner Lucy. Natsu has a pretty close connection to his fire powers, with his mastery of fire comes from Dragon Slayer magic. This allows him to literally eat fire to power himself up.
In order to eat fire, he also has resistance to most kinds of flames. In fact, his fire abilities have been compared to a dragon's. His flames can burn something into nothingness, so it's no wonder why he's sometimes called a demon-lord.
Kyujuro Rengoku (Demon Slayer)
Rengoku Kyojuro was one of the best new characters in Demon Slayer, partly due to his actor Satoshi Hino, as fans loved his kind yet extremely direct personality.
Like all Demon Slayer Corps members, he uses a fancy breathing style to fight demons. His style, Flame Breathing, mimics the original style, Sun Breathing, closer than any other. This allows his blade to literally burn things it cuts, and even frequently leaves fire behind its swings. It's not as extensive as other fire users, but Rengoku's relentless style still makes it work for him.
Shoto Todoroki (My Hero Academia)
It might be hard to call Shoto Todoroki a "fire character" as he also has extensive ice powers. However, his fire powers are still more than formidable. Together, he's one of the most powerful students in My Hero Academia. There's a backstory behind his usage of fire, though.
He's the child of the perpetual second-best pro hero, Endeavor, who used fire powers. While his might was great, he specifically wanted his child to surpass him. So much so that he bought his wife for her quirk so his child could have mastery over two equal powers. Shoto originally refused to use his fire out of hatred of his father, but once he started using it he became unstoppable.
Mereoleona Vermillion (Black Clover)
Being a member of the prestigious Vermillion clan, it is clear that Mereoleona was going to be a threat. While she didn't have very many fights in Black Clover, she made up for it with overwhelming power. She spends time as the captain of the Crimson Lion squad. Her authority is well earned, as she remains almost entirely undefeated.
She's called the Lioness of the Magic Knights because it isn't just the flames from her grimoire that are dangerous. Mereoleona is also a tough physical threat who is also skilled in martial arts, and as a result, made quite an impression on those who watched the hundred-plus episode adventure.
Muhammad Avdol (Jojo's Bizarre Adventure)
Muhammad Avdol is mostly a side character to the Joestar party in Jojo's Bizarre Adventure. However, it's his worldly knowledge that helps contribute to making Jojo's Bizarre Adventure Part 3 a great Part. He acts as a tour guide for the group, spicing up travel with his knowledge, and also spices up combat with his fiery Stand, Magician's Red.
While the Stand abilities in Jojo have a reputation for being strange, as they are spirits controlled by the user that only other Stand Users can see. Magician's Red's powers are rather basic, though, simply being fire manipulation. He can still use this in a ton of ways, though, from shooting fire to making fire constructs. He can even create flames that sense life energy.
Sailor Mars (Sailor Moon)
Sailor Moon has a lot of great characters, and in the case of Sailor Mars, she went from being calm in the manga to hotheaded in the anime. However, this isn't a bad thing, as she's one of the most beloved characters and has some of the best quotes in the Sailor Moon anime.
Rei Ofuda was the third Scout to be introduced and has a bunch of powers. These include clairvoyance, which is reflective of her role as a shrine maiden. Perhaps because of her Miko training, she can actually use her powers in civilian clothes as well. However, this all pales in comparison to her fire powers, with which she can purify spirits and create constructs.
Roy Mustang (Fullmetal Alchemist)
Mustang is one of the most powerful forces in Fullmetal Alchemist. Not only is he a powerful military officer, but his alchemy is often described as the most deadly. His flame alchemy allows him to create large plumes of flame that can scorch entire corridors. While he says he has a limit, we never see it, as he frequently lights up foes repeatedly to no downside.
He's not just big explosions, as he can also create pinpoint flames. He rarely loses a fight in the series, constantly lighting up opponents with flame. He does have two weaknesses, being his powers don't work in the rain, and his glove that lets him do it can be damaged. However, with Lieutenant Riza by his side, he's able to make up for these downsides.
Shinra Kusakabe (Fire Force)
Shinra Kusakabe is the protagonist of Fire Force and a true hero. Most characters in his universe are pyrokinetic but with his Ignition ability and Devil's Footprints techniques, which causes flames to come from his feet, makes him stand out.
He uses these flames to fly, giving him intense mobility. However, he can generate them to accelerate his kicks for more power. Within him is also an Adolla Burst, a link that connects him to the origin of all flame. Shinra is one of the most powerful fire-users in a universe full of them and is even stronger in the manga.
Genryusai Shigekuni Yamamoto (Bleach)
Genryusai may be an old man, but he shouldn't be underestimated, as he has one of the most powerful Zanpakuto in all of Bleach. His sword, Ryujin Jakka, produces a flame so hot that it vaporizes anything in its path, and other Soul Society members who fight with seemingly stronger techniques fear him.
The flames Genryusai creates simply cannot be blocked or avoided. They burn whatever comes before them into nothing. This makes the common way to beat Genryusai simply to take him down before he can use it, or stop him from using it. These flames are the most powerful in anime, and anytime Genryusai appears Bleach audiences know things are heating up.
Portgas D. Ace (One Piece)
Portgas D. Ace from One Piece is not the strongest fire-user in anime. However, as Luffy's adoptive brother and the son of the Pirate King, he's one of the manga's best characters. Even after Ace is gone from the plot, his influence is felt on his brothers Luffy and Sabo.
As with most powered characters in One Piece, Ace got his powers by eating a Devil Fruit. However, the Flame Flame fruit he ate was a Logia Fruit, which offered even more power. Not only could he control flames, but he could also turn into fire. This allowed him to avoid attacks by simply shapeshifting into flames and allowing attacks to pass through him. His body was not only his best offense but also his greatest defense.