The entire class was lounging around all looking pretty lifeless.
Well, I can't blame them, after that miserable failure.

Flashback

Koro-sensei lays on his chair, looking as if all the life has drained out of him. "I'm dead. I'm already dead. For all that to be out in the open...I can't go on living."

"Now, did you happen to notice anything while you sat through our top-secret video, Koro-sensei?"

Suddenly hearing water splashing, he looks down in surprise.

Water! But I didn't sense anyone pouring it in! It couldn't be...high tide!

Stuff happens and the snipers fails to hit the target
....
....

[A/n): Yeah right, I'm not that lazy]

"Someone must shorten the support pilings on this chapel." Terasaka scoffs as the eight top testers go in a circle around Koro-sensei.

"Boat-sick, shamed, and now waterlogged...you've slowed down quite a bit," Rio said, and everyone points their guns at him.

"Now for the main event...a promise is a promise. No dodging, now." Terasaka said.

Kayano swallows slightly, looking at Ritus on her phone as she said, "Commence operation."

Isogai yells, "Begin!" After everyone shot off his tentacles, Ritsu said, "5 seconds elapsed."

Karma, Kayano, Hara, and Takebayashi starts the engines on the speedboats, going in four directions. A rope is connected to each speedboat, the ropes are tied to the chapel wall, and the walls collapsed.

Karma laughs. "Did it come apart?" Kayano asks worriedly.
Takebayashi huffs, pushing up his glasses, while Hara shouts, "Yesss!"

"35 seconds elapsed."

The rest of the students come out from the water, each on a hoverboard as they quickly create a cage around Koro-sensei, making sure he can't get out.

"Koro-sensei doesn't do well with sudden changes to his environment," Nagisa shouts.
"From the chapel to a cage of water!" Sugino continues.
"It'll confuse his weakened tentacles and lower his reaction speed even further!" Maehara ends the sentence.

"53 seconds elapsed."

"Commencing volley.
Taking aim.
The area around Koro-sensei:
1 meter in total." 

Immediately, everyone starts shooting around Koro-sensei.

"Koro-sensei is highly tuned to attacks that make contact." Isogai exclaims.

Rio yells, "But we're actually not going to aim at him!"

  "We'll block his excape path with a hail of bullets!" 

"And that's not all!" In the water, two lights can be seen, with Rinka and Chiba in it, holding rifles, poised exactly at Koro-sensei.

The final blow...  Goes to those two!

The ones onshore are two dummies infused with their scents! By alerting him to the shore while in the chapel and changing the setting to a water cage, they've created a whole new sniping target! 

"Game over!" Ritsu announced, as they hit the trigger.

Flashback ends

"Come on guys cheer up" i shouted. "At least now you can take out all your anger on korosensei." I held him up and smiled angelically, while releasing a menacing aura.

"At least someone can stay positive. Then again what did you do the entire time. I didnt even see you." Terasaka scoffed.

"Well the funniest thing happened.
Right before the assassination i had the sudden urge to go to the bathroom..."

Suddenly i was lifted up by the collar of my shirt. "Don't give me that crap."

"Haha i thought i might cheer you up"
I expression turned into a glare. "If you want to know where i was, ill give you a hint. Where do you think the water from your hover crafts comes from."

——————————————————————
[a/n) with a straight face: the ocean thats where