Jiraiya. The clam genjutsu is overcome through the use of Tengai Hōjin, with the technique allowing him to detect any and all movement which takes place within the enveloped area [
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][
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]. The use of Kage Bunshins will also increase the likelihood of him locating the summon. If the clam is discovered, Food Cart Destroyer should be enough to subdue if not totally destroy it. The location itself will actually play into Jiraiya's hands since the intricate network of pipes grant him plenty of time to prepare his Sage transformation.
Now, Jōki Bōi is a threat, but ultimately, it shouldn't be something Jiraiya is unable to triumph over, especially if it can be distracted with clones, boss summons and the like. It possesses an impressive amount of speed [
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], yet this movement is inferior to a Jiraiya who has activated Sage Mode. Further, the effectiveness of it's explosions will be lessened if taking place in Amegakure, and the threat posed to Jiraiya even more so if he's constantly on the move (as he was against Pain). I doubt Jōki Bōi is surviving being summoned into Jiraiya's Toad Stomach summon. It's also worth noting that Nidaime Mizukage is left extremely weak and in a vulnerable position whilst this jutsu is in play [
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], and as such, Jiraiya would be presented with the perfect opportunity to strike the decisive blow (though of course, this is dependent on him possessing precise knowledge on Nidaime Mizukage's abilities). Senpō: Goemon should be enough to destroy the Mizukage and overcome his Hydrification technique. Gama Rinshō also ends the fight.
