Shinkuu Taigyoku IMO one bigger bullet should be easier to use then multiple smaller bullets. is likely to be rank = or -1 Shinkuu Gyoku for skill using it.
- Katon: Endan (Fireball) - C-rank; 0~10m range. Seems about adult human height radius.
- Katon: Dai Endan (Great Fireball) - B-rank; 0~10m range. Double to triple the fireball size of regular Endan.
- Katon: Ryuuka no Jutsu (Dragon Fire Technique) - C-rank; 5~10m range. Used by Sasuke in Forest of Death.
- Katon: Gouryuuka no Jutsu (Great Dragon Fire Technique) - B-rank; 0~10m+ range. Used in Sasuke vs Itachi final fight.
- Kamitachi (Cutting Whirlwind) - C-rank; 0~10m range. Used by Temari against Tenten in Chunin Exam.
- Dai Kamaitachi (Great Cutting Whirlwind) - B-rank; 0~10m+ range. Used by Temari against Tayuya during Sasuke Retrieval Mission.
- Suiton: Baku Suishouha (Bursting Water Collision Waves) - B-rank; 0~10m+ range. Expels a bunch of water to flood an area. Used against Team Gai during Gaara Rescue.
- Suiton: Daibaku Suishouha (Great Bursting Water Collision Waves) - unknown; 0~10m+ range. This is the water bubble Kisame used in his first fight with Bee.
- Suiton: Suikoudan no Jutsu (Water Shark Missile Technique) - B-rank; 0~10m range. Used during the Konoha Akatsuki fight pre-time skip.
- Suiton: Daikoudan no Jutsu (Great Shark Missile Technique) - unknown; 0~10m+ range. Used at the end of the Kisame vs Gai fight, and uses the opponent's chakra to increase its power.
- Suiton: Goshokuzame (Five Sharks Eating) - B-rank; 0~10m+ range. Used against Team Gai during Gaara Rescue.
- Suiton: Senjikizame (Thousand Sharks Eating - unknown; 0~10m+ range. Used while trying to sneak Kisame's summon past Gai.
In three cases listed, there was a power increase between the two versions while keeping the same general range. In three cases, there was a range increase in addition to the power increase. This also sets a pattern where by tacking on "Great" or the like where there is an existing version without that word in canon, makes it more powerful. In the three cases where we know the ranks of both jutsu, the one with "Great" added to it is +1 rank to the version without the word.
So following the pattern, Shinkuu Taigyoku would be more powerful than just Shinkuu Gyoku. Also, Danzo used both techniques in his fight with Sasuke. Shinkuu Gyoku was used early on after Izanagi came out and Sasuke only had his imperfect Susanoo come and go. Shinkuu Taigyoku was used after the perfect Susanoo appeared. Generally speaking, people don't use weaker jutsu as they move through a fight on this level. Particularly when your opponent is throwing around Amaterasu, Tsukiyomi, and Susanoo and you have a time limit (Izanagi Sharingan use) to finish the fight in.
Something to consider. Each small air 'bullet' requires a small amount of chakra to hold it together over 0 to 10m, versus the chakra needed to hold a large ball of air together for up to and over 10m.
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I think I shall place Shinkuuha as A-rank. It seems like a more AoE version of Kaze no Yaiba, given that he used it to take out several airborne Wood ninja attackers. However, he DID apparently use it in his fight against Sasuke right after Sasuke summoned a Hawk. Sasuke jumped over the attack while the hawk dropped below it. So it can take out more people than the Kaze no Yaiba, but is easier to avoid unless in a spot where one can't dodge. Seems like a fair enough trade-off to keep it in the same rank range. From this, the Shinkuu Renpa would then likely be B-rank or S-rank, depending on whether each air blade fired was weaker than or equal to the Shinkuuha's sole blade.
Alternately, the fact that it can be dodged fairly easily if you're in a position to do so could give it a B-rank and Shinkuu Renpa could be an "upgunned" version of it to counter the dodge issue by spitting multiple Shinkuuha. I could see combining it with the suction of Danzo's Baku summon to be S-rank strength (and be able to crack open a perfect Susanoo).