Great Demon Coronzon paused for a just a moment.

He had been waiting for that.

Accelerator closed the fingers he had opened like claws and pulled back his clenched fist.

He could use a large swing of the arm. He had created enough of an opening for it.

Just like a certain boy, he poured all his strength into his fist and released it!!

It was like an explosion.

An invisible shockwave scattered around the center of the hit and the old walls of
Edinburgh Castle shook.

And yet the #1 monster clicked his tongue a bit.

“You redirected the vector.”

“Kee hee hee.”

Coronzon had indeed slid backwards.

But she had avoided a direct hit to the face. Her absurdly long hair had formed several
bundles that layered themselves in front of her. Each of those bundles and even each
individual hair bent and negated the vector that should have passed through it. A strange
sensation ran through Accelerator’s fist and back through his bones, like he had punched
a powerful spring.

And.

“Ee hee. Nee hee hee. Kee hee hee hee hee hee hee hee.”

Something like a balloon inflated and burst in the center of the #1’s chest.

This was not blood, flesh, or bone.

It was something more invisible, harder to understand, and yet of great importance.

“Tch!!”

“I am a demon, but not from the Qliphoth. I am the Great Demon that dwells in the Abyss
of the Sephiroth. The Sephiroth’s ten Sephirah and twenty-two pathways are also a
conversion table for producing the supernatural by connecting the great universe of the
world with the small universe of the body. Do you feel it? An arm is formed from Chesed
and Gevurah and its five fingers control the five elements. The middle finger controls fire
and the red of blood, which symbolizes the activity of the heart. You made a mistake when
you accepted the rebounding force to measure how much damage you had done, one who
remains in the human realm.”

Simply put, the damage passed from his fist, up his arm, and to his heart.

Carelessly touching her would harm him.

When you thought about it, that was a lot like Accelerator’s own reflection.

He would not have used that method had he known about this.

And he of all people would know it was too late to complain after the fact.

[...]

“You’ll feel better if you cough up that blood, you know?

-Shinyaku Toaru Majutsu no Index Volume 22 Chapter 1 Part 4