Here we have 2 most loved character from Naruto.
Itachi uchiha (17 years old)
In 3rd databook they both have 35,5 in total stats. Jiraya is more like ninja who have big amount of chakra, his stamina is better than itachi’s that makes him better in physical battle + sage mode which gives him nature energy : physical strength, better sense abillitys, chakra. But Itachi is different type fighter, he prefers to end fight faster, because he don’t have enough chakra and stamina. His visual abillitys and intellect gaves him adventage in every moment…..
If we want to make it clear , who can end this fight faster… I’d go with Itachi, because of his visual powers.
At 13 he was able to catch Orochimaru in genjutsu ( only 3 tomoe ) , in that moment orochimaru had more resistance in genjutsu than jiraya , but Itachi was able to cut his hand off .
Even orochimaru stated that Itachi was stronger than him. As i remember Orochimaru without arms and bad body was fighting 2 sanin with kabuto… and itachi could beat his healthy version. He is more like 1 vs 1 fighter, at 17 im sure he would beat jiraya easily.
Tsukuyomi was enough to kill kakashi , without tsunade he would be dead right now.
In book of “dark knight” Itachi approached Izumi and placed her in an extremely powerful Tsukuyomi, where she lived the entire life of her in just 0.0000000001/th of a second. Genjutsu was peaceful but Izumi died, this genjutsu is only one which can kill it’s enemy. No one can analyze this kind of information in that period of time, that’s why brain is dying. As kakashi mentioned u can’t cancel Tsukuyomi, Jiraya don’t even have information about this Jutsu, so he is not going to look aside from him. If i will take full arsenal Itachi can use kotoamatsukami and izanami too.
If Itachi will change Jirayas memories , battle will be over. Kotoamatsukami can even make Jiraya kill himself In a way that he will be happy for that (thinking doing that was the right choice). That’s why Kotoamatsukami is on of the strongest genjutsu. After casting this genjutsu , planted memories become your own, that’s why no one can release themselves from it.
Jirayas sage mode is useless here , itachi can end this battle in instant, but without that he can just go against Jiraya with 2 artefacts : Totsuka, Yata. This two spirit weapons are enough to make him invincible as black zetsu stated who knew whole history of shinobi.
People are saying that Itachi left fight with jiraya because he feared him. Thats just absurd , he was protecting village and jiraya was one of the strongest konoha ninja in that period.
Obito was scared of Itachi, because only thing that could stop him from destroying the village was itachi, Also hiruzen said that he joined akatsuki to protect village.
And the last thing he can go against Jiraya with Izanami. This jutsu needs to record 2 sensations like : caused for example with substitution or fire ball jutsu and caster will lock enemy in loop.
It was used on izanagi users, because they were changing their own reality, that was blinding them and it was wrong. If Itachi will cast Izanami with 2 recorded feelings, Jiraya will get free after 1-2 weeks because, he don’t even have any information about that. This loop is absolute.
Itachis techniques, Kotoamatsukami, tsukuyomi and izanami can’t be countered as normal genjutsu they’re special genjutsu if you are interested what is the difference, you can read the explanation here: FACTS CHECK: GENJUTSU