The techniques below are easy ones to identify as a stream, so I'll teach you these first. Now, your job is to list all D-A Rank Katon techniques, which would obviously fall under the 'stream' category. I won't teach you the ones you've already learnt, but I want to test your knowledge.
(Katon: Gōen no Jutsu) - Fire Release: Great Flame Technique
Rank: S
Type: Offensive
Range: Short - Mid
Chakra Cost: 40
Damage Points: 80
Description: The user does one handseal and inhales while molding a great amount of chakra into their lungs and expelling a large stream of flames from their mouth. The user has control over the concentration of the technique, being able to produce a narrow jet of flames, highly concentrated or one that will widen along its range. The flames are hot enough to quickly evaporate large quantities of water within a relatively short amount of time.
This was used by the Sarutobi clan against the Ten Tails. This is one of my most favorite fire techniques. It's pretty simple. You weave one handseal, inhaling a large amount of air while you gather up a very large amount of chakra in your lungs. You mix the inhaled air with your fire chakra and exhale out a super tremendous stream of flames, akin to a flamethrower. Either, you can focus your chakra at one singular point to make the stream very concentrated, which does greater damage, although it loses horizontal width then. You can also release it like a normal stream, which would start narrow, but widen as it travels, covering a very wide area, and is very destructive. Even small contact with the flames will turn the opponent into ash. These are so hot that they can evaporate massive water bodies in seconds.
(Katon: Gōka Mekkyaku) - Fire release: Great Fire Majestic Annihilation
Rank: S
Type: Offensive
Range: Short - Long
Chakra cost: 40
Damage points: 80
Description: A technique where the user makes the horse hand seal and then kneads chakra inside his body which is then converted into fire and expelled from the mouth as a massive wall of intense flames, which covers an expansive range in both vertical and horizontal dimensions, making it extremely difficult to avoid. However, due to its massive width and height, the technique is not one of the fastest seen so far.
S-Ranks are beautiful, and so is this technique, which is one of my favorite to use. You weave the Horse handseal and inhale a large amount of air, while kneading massive amounts of Katon chakra, after which you mix the inhaled air with your Katon chakra and channel it to your mouth. You then exhale out the fire, in the form of a massive stream of destructive hellfire which widens in it's range as it travels, akin to a flamethrower. Once the flames hit the ground, it blasts forward, widening suddenly into a gigantic wave of fire. The width is so high, that it covers a very tremendous area as it travels, scorching and melting the very ground as it travels, and rising a certain height in the sky. However, due to the width and the height it possesses, it doesn't travel as fast as a normal fire stream would travel. It is destructive enough to burn the entirety of a forest in mere seconds. The downside is that, due to the unthinkable area it covers, the vision of your opponent is hindered to you, and the vice versa respectively. This is one of the strongest Katon techniques in the manga, as well as in the canon Fire list. A lot of people use this casually, and exploit it way too much. It required upto 10-15 Suiton users to extinguish the flames, in the manga, and the anime.
(Katon: Gōka Messhitsu) - Fire Release: Great Fire Destruction
Rank: S
Type: Offensive
Range: Short - Long
Chakra cost: 40
Damage points: 80
Description: A technique where chakra kneaded inside the body is converted into fire, and then expelled from the mouth in a massive stream of intense flames, after doing the Rat → Ox → Dog → Horse → Monkey → Boar → Tiger hand seals. The technique has an enormous range and can cover a huge area. When it was used by Madara Uchiha, the massive scale of the technique was such that, in comparison, his incomplete Susano'o seemed small. The main advantage of the technique is that it can be used to burn large areas in an effect in everything similar to a flamethrower.
Another of my favorite techniques. Call it a sibling of the previous technique. This was used by Madara from within his Susano'o against the 5 kages. You weave a certain set of handseals, and knead Katon chakra in your lungs, exhaling out a super powerful stream of flames. The stream is so wide that Madara's incomplete Susano'o itself seemed like an ant in comparison. You can burn down entire forests and wipe out entire landscapes in seconds with this, given that the stream has a very high temperature and can turn down everything to crisp. Again, it works like a flamethrower, destroying everything in it's path. This is faster than the previous technique.