In reality, it is pretty unlikely that any character from Azula is tactical and explosive. But because of these traits, Azula is incredibly powerful and would probably go undefeated by many of the cast within Korra, including the villains.
If Azula had been in Korra, she definitely would have been an extreme threat, maybe too much for the new Team Avatar to handle. She would laugh in the face of the rest of the villains who attempted to get in Korra's way and would likely see all them as nothing more than bugs. Typical Azula things. Here is a list of 10 villains in The Legend of Korra that Azula would totally annihilate.
Baatar Jr.
Baatar Jr. was a secondary antagonist in the series and did some pretty questionable things that definitely earn him a spot on this list with the rest of the villains from the series. He betrayed his family to side with Kuvira, his fiance, in order to leave his father's shadow.
Baatar, however, was nothing without Kuvira. He was an engineer, not incredibly powerful, and definitely brainwashed into believing Kuvira's ways. Azula would have found him pitiful and destroyed him without a second thought.
Desna & Eska
Azula is ruthless. She doesn't care who she burns down in her path, and her streak of crazy makes her all the more powerful. Eska's crazy jealousy over Bolin doesn't even hold a match in comparison to Azula.
These two water benders would have faced some serious trouble when combatting Azula and probably would loose near immediately, even though the battle would have been two against one.
Hiroshi Sato
Hiroshi Sato was the corrupted father to Asami Sato. He aided the Equalists in the fight against benders and made the equipment that would stun their foes. Azula has some experience with those who could take away bending as she was extremely close to Ty Lee and was attacked by her, rendering her useless. Surely, Azula would have learned her lesson and done everything she could to avoid that situation.
But even without bending, Azula is a strong combatant. She could easily best Sato in hand-to-hand combat at any point.
Tarrlok
Tarrlok was a simply corrupt politician. He had skewed morals and liked to play dirty, stopping at nothing to prevent the Equalists from taking over. While Azula may have liked his mindset, she probably would have eliminated him just for not agreeing with her.
Tarrlok was the representative of the Northern Water Tribe, and if Azula wasn't able to manipulate him for his power then surely she would have simply gotten rid of him.
Amon
As mentioned with Hiroshi Sato, the chi-blocking moves done to prevent Azula from bending may prove a bit problematic for her, however, she is sure to overcome. Azula would surely force Amon's hand and make him water bend just because he is not powerful enough to stop her alone.
He may stop her from bending, but there is no way he would be able to hold Azula down long enough to take away her bending completely. Azula would best him in hand-to-hand and in bending at any time, her flames may even leave an actual scar on top of his fake one.
Unalaq
Unalaq is a complicated villain due to his family ties to the protagonist of the series, something Azula may even be able to sympathize with if she weren't so bent on herself all the time.
However, like all the rest on this list, Azula may see Unalaq as a threat to her own way of living and may want to get rid of him. Like she did with the Dai Li, she would try to manipulate him into listening to her only, and if that doesn't work, she would simply "get rid of him."
P'Li
P'Li is a combustion bender and assumed daughter of Combustion Man from the original series. She is a long time member of the Red Lotus and Zaheer's girlfriend. But even though she has the same skills as Combustion Man (whose name we still don't know), she is really no match for Azula.
P'Li's skills come from her ability to make explosions, but Azula's fire bending is like an explosion itself. P'Li may be able to direct her combustions elsewhere, but she is no match for Azula's hot and abundant flames nor her lightening.
Ming Hua
Azula can pretty much take on the entirety of the Red Lotus, maybe even multiple at a time. Ming Hua is no exception.
This bender has no arms so she uses her water bending to make up for it. But due to Azula's flames, there will just be a ton of steam in the area, and Ming Hua's water arms may be reduced to nothing. Ming Hua is an excellent fighter, but it still seems like nearly no one would have a chance against Azula.
Ghazan
Azula is probably the greatest villain in the Avatar universe. Ghazan is an earth and lava bender. Against any other bender, he may prove to be an extremely difficult enemy, but against Azula, he once again wouldn't amount to much.
Azula has been seen combating against a number of earth benders and has seemingly been victorious each time. She is extremely agile, something that earth and lava are not, and can dodge any number of blows. She would be too quick for Ghazan and may use the lava to her advantage.
Zaheer
Though Korra's biggest adversary, it is unlikely that Azula would have as many problems as the young Avatar. Zaheer became an air bender but it is likely that Azula would have attacked him even before he had that chance.
She would have found his philosophical viewpoints tiring and annoying and would have probably attacked him before he had the chance to attack her. In a fight between air and fire, the battle would have been tough, but Azula seems to know no bounds and would have been victorious in this combat.
