Jiraiya is one of the three Legendary Sannin along with Tsunade Senju and Orochimaru. If Orochimaru is the evil member of the Sannin, then Tsunade is the neutral member and Jiraiya is the good member. Everything he does is to bring happiness to those around him, including himself.
During the Second Great Shinobi War, when the Sannin came across the war orphans of Nagato, Yahiko, and Konan, it was Jiraiya who decided to take them in and train them. He did this not only so that they could return to a healthy life, but also because he believed Nagato would one day bring peace to the world.
But, although he’s one of the Sannin, perhaps his more famous title is that of the toad sage. Like his two teammates, Jiraiya is also in possession of a powerful summoning pact, this time with the toads of Mount Myōboku. However, unlike his teammates, he nearly mastered senjutsu or sage mode.
It was during his time training at Mount Myōboku when he learned of a prophecy stating that he would be the teacher of the one who brings peace to the world. After this, he set off to find this legendary pupil, and over the years he trained three worthies of note: Namito Namikaze, Nagato Uzumaki, and Naruto Uzumaki.
Interestingly, despite being extremely powerful and well-respected, fighting was never really Jiraiya’s passion. Instead, he wanted to be an author, which he managed to become successful. Traveling around the lands in search of new material to write about was also an excuse to search for his pupil of prophecy.
In the end, Jiraiya died at the hands of Nagato. He used his last moments to send a message to his final student, Naruto, in hopes that he would turn out to be the one to bring peace to the world.
To start, Jiraiya can use Earth, Wind, Fire, Water, Yin, and Yang release. Of these chakra natures, the ones he uses most frequently are Fire, Water, and Yin release. The commonly used chakras are used explicitly for his various toad sage jutsu.
Along with his toad summoning jutsu, about half of the jutsu Jiraiya uses are directly linked to toads in one way or another. He can cast toad genjutsu, he can turn into a toad, and he can spit flaming oil which is also somehow toad-like, among others.
And, thanks to his toad sage mode, he’s able to take in natural energy to replenish his chakra on the go. Unfortunately, since he never wholly mastered this skill, he has to keep his hands together to do so. This requirement makes fighting more difficult. Jiraiya also gains some toad-like physical characteristics.
One of the other major jutsu he uses is the Rasengan and its variants, though he never added a chakra nature to it. The Rasengan became his go-to jutsu due to its relative ease of use and efficiency. One well-placed Rasengan can completely take out his opponent.
The rest of Jiraiya’s jutsu appears to be specific to him and involve his hair. He can harden his hair to use it either as a defensive wall or even fire it off offensively as needles. It’s unclear if these jutsu are some clan or bloodline jutsu. It’s unknown what clan Jiraiya is a member of, but as with his sage mode, he only uses them when he gets serious.
When Jiraiya is serious, there’s almost nobody who can stand up to him. Yes, he dies to Nagato and his Rinnegan, but it’s implied that the only reason their battle ended this way was due to Jiraiya showing mercy to his former student.
There are seven humans in existence that have successfully used sage mode. Sage mode helps to put Jiraiya’s abilities into perspective. The list of Sage mode users is short, starting with Hashirama Senju, Jiraiya, Jūgo, Minato Namikaze, Kabuto Yakushi, Naruto Uzumaki, and most recently Mitsuki. So, this skill alone puts him well above most ninja.
Jiraiya is also a mid-range combatant, able to use both close range attacks like the Rasengan and long-range attacks like the Hair Needle Senbon. And, through his fight with Nagato, we see that he can even go toe to toe with multiple high-level and skilled opponents at once.
So, who could beat Jiraiya other than Nagato? Hashirama Senju and Madara Uchiha are two viable options, but they’re so powerful they can beat just about anyone other than Kaguya Ōtsutsuki.
I’d say Itachi Uchiha, but we know that Itachi is no match for Jiraiya either because the one time they came face to face Itachi opted to flee despite having Kisame at his side. He knew that even both of them combined would struggle to defeat the toad sage.
The only way to defeat Jiraiya is to take him by surprise. However, if he gets the chance to figure out his enemy’s abilities, then the battle is essentially over.
Since Jiraiya is almost a jack-of-all-trades, he can fit on any team composition except tracking teams. However, thanks to his skill set, he would be most useful when paired with a powerful genjutsu user such as Itachi Uchiha.
The reason for this is that Jiraiya’s genjutsu are all tied to a summon. So, if he has a teammate who can focus on genjutsu, then Jiraiya can use his chakra for the other, more offensive jutsu in his arsenal.
But, since Jiraiya can use genjutsu of his own, a powerful genjutsu user isn’t necessarily needed. Instead, he could opt for someone who can help him locate his targets. Any Byakugan user would be the best pick for this role, but there are a few others who could be capable too, such as anyone from the Aburame clan.
Without any way of tracking down or locating his opponents, Jiraiya’s power isn’t all that effective. If he can’t find his opponent, he can’t defeat them. So, Jiraiya, Itachi, and Neji would be a pretty efficient team. They all have specific strengths which work well together, and yet they’re also competent individually.