The Sannin’s "three-way deadlock" is called "Sansukumi"
It’s the Japanese variant of “rock, paper, and scissors”. It goes something like this:
“The oldest sansukumi in Japan. A snake swallows a frog. Frogs are defeated by snakes, but if their opponent is a slug, they easily pick it up with their tongue and eat it. However, snake venom has no effect on slugs, which are defeated by frogs, and the mucus in their bodies dissolves snakes (which are supposed to be stronger than frogs). (However, there are species in the family of slugs that prey on slugs.) If the frog eats the slug at this time, it will be eaten by the snake afterwards, so the slug cannot be eaten. Snakes and slugs are in the same state, and all three are stuck in a deadlock (Source).”
This is almost exactly as how the battle went down in Kishimoto’s canon: Manda massively overpowered Gamabunta, but as soon as it tried to perform strangulation on Katsuya, it just burst into many tiny bits; Katsuya’s venom forced Manda to shed its skin and burrow its way underground. This gives Katsuya a defensive advantage against the brutal power of Manda and the acrobatic nature of the frog: it simply can’t be eaten; hence, it can’t be defeated by pure brute force. Remember, Katsuya’s little part was inside Naruto’s sleeve when he transformed into 6-tails and later sucked into Nagato’s Chibaku Tensai, both of which didn’t even scratch it; it also crawled atop people when Deva used the massive Almighty Push, which is simply a more powerful form of Shinra Tensai; but it was so resilient that not only did it not sustain any damage itself but also the people under it escaped unscathed. That’s how durable Katsuya is. (Yes, Kishimoto has given this a little bit of spin; but it’s mostly still the same: Tsunade’s magic in The Tale of the Gallant Jiraiya aligns well with her healer counterpart in Kishimoto’s manga; so the sexism charges are fairly baseless.)
So keep this deadlock aspect is mind the next time you tackle the manga. Kishimoto did the right thing by associating Katsuya with healing, durability, and resilience; because without these three factors, it’d never be able to mass-heal people.
