I do not own Naruto, if I did Itachi would be the Fifth Hokage or the founder of his own village.
Yagura is short, strong, successful, but one thing he isn't is short-tempered, despite what his height suggests. He is very patient. So when he is put inside the weakest Genjutsu ever, that just so happens to make him become a fanatic, he feels entitled to flip out.
"I had on job. ONE JOB!" Here, the esteemed Mizukage can be seen stomping around his mindscape. A lake, a few trees, and a light mist. A peaceful place shattered by his temper tanrum. "Protect the village, protext the land. Sounds easy enough. But NO, a simple D-Rank Genjutsu takes me out! How? HOW?!"
Through all this, at the bottom ofnthe lake, Isobu just watches, for the Isobu is also patient.
You see, while Yagura is flipping out, Isobu keeps the appearance of capm. Unlike Yagura, he is well aware that getting angry will do nothing. He is not atnall angry at seeing the Sharingan, or at being controlled. Not bitter at all.
Yagura stops his yelling, and just stares as a dark blue chakra erupts from the Bijuu. Not angry at all, just irritated.
"Yagura, calm down. We can survive this. We will survive this." The calm statement, Isobu is sure, will definitely calm his host down.
His "host" decides to die at that moment, and whatever composure the Isobu had left. He ran, and ran, and ran, untill he reached his lake. Then the weekly meeting with the other Bijuu began.
"Isobu are you alright? We felt yo-"
"DO I SOUND ALRIGHT?!!" For the first time, the Isobu isn't patient. "I AM HIDING IN A LAKE! NOT AN OCEAN OR SEA, A LAKE! THIS IS AN OUTRAGE! Did I mention how great us was to hear from you all? You see, I need help."
"Riiiight. Well, I'll send my host to help you." The Matatabi is suprisingly helpful.
"Right. Thankyou. Welp, I'm going to sleep."
"This meeting is not ove-"
The Isobu sleeps.
The first time he wakes is to receive a message from the Matatabi saying his host needs help, but he's sure he can handle it.
"Damn you, Isobuuuu!"
"Who's Isobu?"
"A ninja with a high bounty for a Bijuu to know his name."
The second time he wakes, Chomei is flying over his lake. A well placed splash of water ends that. As he sinks back under the lake, he misses Hidan amd Kakazu draggjng the Bijuu away, hoping Pain wouldn't kill them for being late.
The third time, two powerful ninja, Tobi and Deidara, are nearby, and as the bombs sink below, he goes back to sleep. After several bombs drop, amd they get no reaction, Deidara and Tobi sulk away.
At the peak 4th Shinobi War, the 10 Tails never appeared. As all the shinobi watch Obito get beaten by Madara, he remembers the one Bijuu he forgot, that he made sure he had. With the last of his chakra, he summons his last resort, the bloody tomato. The combination of blood and tomatoes is something no self respecting revenge.driven Uchiha can resist, and though he was saving it for Rin, it would have to do. Throwing it as far away as he could, he waited. As Madara lunged for the bloody tomato, he lunged to the left into dirt.
"That's not a part of the script!"
Itachi comes back from the dead and stares at him. Obito feels death, and knows what he has to do. He runs.
He runs, and runs, grabs Deidara's soul, runs, wait ,what, runs, and reaches a familiar lake, while wearing a familiar mask. Quickly switching back into his Tobi persona, he promises to make the Isobu pay.