I hope i dont burn myself-korra

[Inashi]

Strong points
No hand seals and the added bonus of knocking the opponent out can create some large scale attacks with the effect to knock the opponent out
Weak points
I'm not sure if the jutsu can affect the user if the enemy were to reverse the direction of the technique. Since you are close the enemy, if they counter or dodge, you could potentially be left open
Combinations-strategies
Combining it with Fire Release: Mist Blaze Dance Technique could create a large scale attack with the possibility of this jutsu's knock out effect. Also, using Wind Release techniques could make the jutsu larger with this same effect.

Ways to counter this technique
A larger or stronger Suiton Jutsu will block the attack, but I'm not sure if the immense heat would evaporate the jutsu. Using a large Doton Jutsu to block the attack would work, as it would divert the flames, even if the heat is greater than a normal Katon Jutsu.

You Doing the jutsu.
The user stands in close proximity to the target and builds up Katon Chakra in their body. It is then expelled from the mouth, but this isn't a standard Katon Jutsu, if it connects with the enemy, they might collapse due to the immense heat this jutsu creates

 

[Korra.]

It would be hard to redirect it back at yourself.

(Katon: Gōkakyū no Jutsu ) - Fire Release: Great Fireball Technique
Rank: C
Type: Offense
Range: Short-Mid
Chakra Cost: 15
Damage Points: 30
Description: After performing the necessary hand seals Snake → Ram → Monkey → Boar → Horse → Tiger, a ninja inhales air, and utilizing a large amount of fire chakra, spews a large fireball from their mouth after blowing through a ring made by the thumb and index finger of the user, incinerating everything in range. The fireball ignites externally. The fire ball can present itself in 2 forms: it can either be created by a stream of fire and sustained as a gigantic ball of flames in front of the user spanning up to short range or be released as a slightly smaller ball of fire which will travel towards the enemy up to mid range.

Do the hand signs and inhale air and combine it with fire chakra and exhale a large fireball from your mouth through a ring made by your thumb and index finger so that your incinerates my clone.

 

[Inashi]

im sorry but things have changed for me. so i cant continue with this training