All Might was flying above Hashima island which that man resides on watching the operation to surround the island with scouting vessels to prevent escape. As they got into position Izuku who was next to him was using quirk sight to try and find the exact location of All for One.
He sees a small flickering red orb near the middle of the island. He tells All Might this and he flies further up in the sky to fly away leaving behind a shock wave disperses some clouds which goes unoticed by anyone below. All Might looks at the spot Izuku pointed out and seeing the vessels now in position begins the operation.
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All for One was laying on the medical bed resting after being examined by the doctor. He was seething as his plans to finally take back what was rightly his had to be delayed even one of the nomu was taken. An alarm sounds through the facility. This surprised him and he quickly got up to meet the intuder. Before he can get near the door a familiar face bursts through the it.
"All for One you evil ends here."
He is launched back by an air cannon from the villain.
"All Might how nice of you to visit. I do wonder how you got my address but no matter you've brought me just what I wanted. "
All for One rushes to the hero with a speed quirk to punched him with a strength enhancer boosted by springlike limbs. This blows a hole through the facility into the open air and All for One flies above All Might touting his superiority but that doesn't last long as All Might launches himself at high speed using Float and Gearshift to punch All for One as he used some body enhancers and spearlike bones to hurt All Might on impact. He is then pushed back a few meters in the air having not expected the power of the punch to break through his quirks. He turns and looks to the ground expecting to see All Might but he is punched in the head sending him hurtling into the ground.
He gets up dazed and looks up to see All Might in the air just like her. 'Impossible'. That infuriating smile plastered on his face. He flies back up to retaliate which was dodged. This back and forth continues with the both of them hitting each other blackwhip appearing to negate most of All for One's attacks.
"What's wrong All for One you'd usually be boasting how much more powerful you are."
"You know nothing of power."
The fight got more intense with All Might taking more hits than he did before even with Blackwhip help. Dark beams and lightning can be seen offshore pushing away clouds. They were at a standstill until All Might managed to land a hit with the power of gearshift and half of the collected power from fa jin sending Afo into the ground into a crater. He bloddied struggles to get up as All Might slowly floats down with his cape billowing behind him.
"This is over All for One. It's time to give up.
"Your right... I give."
All Might got close to cuff him but Afo's hand shifts into a blade and tries to stab All Might's heart but he moved so it went into his stomach. His arm now embedded in All Might then shifts into a large barbed mass and using mutalation to increase the damage and to make sure his organs were crushed. Before he could pull his arm out, it was cut off by blackwhip which kept the arm in place to reduce bleeding. All Might collapsed onto the floor shredded organs still inside him along with All for One's transformed arm. All for One let's out a guttural laugh.
"HA HA HA HA HA, you imbecile. Why would you EVER trust a word I say. You'll die just as your precious master did by my hand."
He receives no reply as black tendrils emerge around the wound to cover it up some of the arm still exposed. All Might is silent his signature smile gone replaced by a empty expressionless face as he disappeared from sight. All for One was too stunned to move as All Might's hands were already around his head before he saw him. That blank face conveying nothing but All Might's focus on his task. He saw the face which would haunt for the rest of his days as an insurmountable pressure is felt as All Might's slowly hands closed around him. All for One struggled and clawed for freedom using every quirk in his arsonal but to no avail as every attempt was foiled, restrained by black tendrils.
'Crack'
'Squelch'
'Thud'
The top of his head was crushed, the rest of his body fell to the floor limp as blood poured into the dirt below. All Might collapses on his knees looking at this blood covered, brain matter splattered hand. Finally, he had avenged his master.
Gran Torino appeared at the scene seeing the body of All for One was a satisfying sight to behold but there was no time to waste blood was leaking between the black tendrils as he picked up All Might to get him to safety.
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The clean up of the island was a mess. Thankfully the fight had happened on an island away from the prying eyes of the public. A fake story was drum up to hide the destruction of the island, a fight between All Might and Toxic Chainsaw. All for One's body was collected and brought to a morgue at Jaku General Hospital to avoid public suspicion of the presented story. The Midoriyas were allowed to leave the school though they still had to stay there as the underlings of All for One are still active.
Meanwhile
Under Jaku General hospital was a lab with a stasis pod holding the body of All for One. The doctor was looking at it in sadness and anger. How had All Might found their base on that island? How was he able to overpower his great master? Nevermind he can make him better he just needs more material. If only he could use that boy's quirk, his master would have been unstoppable. This thought causes an epiphany.
"Kurogiri"
"Yes doctor"
"Find Izuku Midoriya and bring him here in anti-quirk cuffs. He is needed to restore the health of our master"
Kurogiri disappears into his portal leaving the doctor alone once again in front of the pod.
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Next Time
Chapter 11 : Abduction
Thanks to AdamKlydeUy, Zibiti, Whoecares_lmfao, CrossChara552, Jokerjay75, 13sdfddfu and Lasagnor for voting. You're all truly wonderful see you guys next time.