"Ughghhhh so much pain"
Aku saw the samurai about to strike him down for good. Couple of ideas had gone through his head.
Send Jack to the future? Hard No he'll still comeback and kill him anyways
Send him to the sun or the end of time? No that sounds way too easy and cliche, sue him he likes a challenge.
Wait a moment, the future that's it!-
The Isekai soul's plan was immediately derailed since the samurai just stabbed him with no monologue or speech about how he was defeated just a quick stab on the head. The pain was worse since he was stabbed through the head.
It seemed that he was still conscious even as he was being absorbed by the sword which hurt a lot.
Was this how his story ended? Being defeated by Jack? This wasn't fair he'd barley had time to get his bearings and get use his powers.
It seemed that his stress over the situation didn't allow him to think clearly and now he was dying.
What does every great villain do when they are dying? Beg the hero to not kill them that wouldn't work for him since he had no mouth no more since his form was distracting.
He was still conscious but he didn't know for how long so he might as well do that song that Cell did when he was dying.
"And now the end is nigh" He was just speaking in his head to no one "It seems that I am not immortal"
He really should've had a back up plan like putting his essence in a person and taking over like a virus like joker did in that one movie or did what OG Aku did and give his essence to a woman like he did with that cult of his.
Yeah that would've had been smart to do but it's too late to think about such things now at his end.
"The foolish samurai, refused to DIE!"
"Ohhh malaise filled all of today" It's crazy in one day he was killed by Jack.
"I did nothing at all, Every Tuesday" Who cares if he was out of tune he was dying.
"Oh yes, oh yes I did"
"But now I'm gone, and now I'm dead"
"A stupid sword, stuck through my head" He felt his erasure happening.
"I ruled Japan, my word was law"
"Bwahahaha, bwahahaha"
"At least the end was quick And EXTRA THICC!" He just wanted to think that before he died.
"I did it! Aku's Way!"
He felt the samurai no... Jack slammed the tip of the sword into the ground as his entire being was being purified for lack of a better term and all he could do was blink.
The tower that housed the unfortunate isekai soul had been destroyed luckily Jack had made it out as it was collapsing.
That was the end of Aku as he eventually become a legend as the story of Jack's victory got passed down generation to generation as the world just simply moved on.