One/three advantages (no obvious ones, be creative):
1. A fast jutsu to perform.
2. is a good combo with wind release: pressure damage
3. if it touched the surface, it's hard to counter uit
One/three disadvantages (no obvious ones, be creative):
1. no long range
2. maybe, if you're being reckless, the fire could hit the user too, because you perform it waaaay too close. (or you're just stupid

)
3.
How you would use it in battle: To deal some damage to the user, or to evaporate a small water source or to cancel a jutsu out that was sent low, on the ground or something.
How you would counter it: trying to avoid the fireball hitting the ground, canceling it out with some jutsu. but if it hits the ground, I would probably create an A rank dome to protect myself
How you perform it (with as much detail as you can): I gathered my katon chakra and focussed super good. I channelled it into my lungs, infusing it with my breath and I performed the Rat → Dog → Tiger Hand seals. I concentrated really good on it and I released the katon chakra out of my mouth. I manipulated it and created a small fire ball. I added a lot chakra to it, and the're was a lot of katon chakra, compacted in the small fire ball. when the small fire ball hit the ground, all the katon chakra was released and a big fire storm was created, dealing damage to everything in it's range!
One/three advantages (no obvious ones, be creative):
1. This jutsu is very hot and can maybe even kill somebody
2. Easy to perform
3. Hard to counter
One/three disadvantages (no obvious ones, be creative):
1. the ground becomes red, so the opponent will know where the lava will erupt
2. The opponent could know when it'll erupt, because of the hand seal which'll be performed
3.
How you would use it in battle: TO DESTROY THOSE MOTHAFOKKAS (purely attacking somebody)
How you would counter it: Creating a large pillar beneath me, lifting me high up into the air
How you perform it (with as much detail as you can): -you created a clone- I gathered some doton chakra and stomped on the ground while releasing the chakra into the ground. I made a small opening in the ground and I gathered a lot of my katon chakra anf focussed very good on it. I channelled it into my lungs, infused it with my breath and I released out of my mouth a very compact and a very hot fire stream into the opening. The fire was so hot that it started to melt the earth and it made his way trough the tunnel. And when the fire/lava was beneath the clone you just made, I performed one hand seal and the ground beneath the clone started to glow and it became red. The lava started to erupt and causing a "fiery explosion" engulfing the clone in lava... *poof*