Aleister burns his body fighting the Magic Gods

“Have you found something to make up for what happened?” asked the golden retriever
walking with Kihara Yuiitsu. “It was clearly a mistake to contact the Magic Gods at that
point. Did you finally learn your lesson now that you have to recover from getting a third
of your body burned so badly?”

-Shinyaku Toaru Majutsu no Index Volume 11 Epilogue


"Honestly, why did Aleister have to thoughtlessly destroy our hidden world? Maybe we
really should've killed him."

"We are not like Othinus," replied the High Priest. "You yourself said so, Niang-Niang.
Not that we can shamelessly call ourselves harmless."

His gentle and soothing voice led Niang-Niang to raise both hands.

But she was not saying she had been persuaded by his virtuous sermon.

"Don't act so high and mighty, old man. You're the one that got pissed and tried to kill
him first."

-Shinyaku Toaru Majutsu no Index Volume 12 Prologue


"Oh, is that you, Aleister? I'm glad to see you're still alive and kicking. Sorry about the
other day. I really shouldn't have let my anger get the better of me at my age."

That was all it took for him to kill.

Rather than follow an exaggerated plan or make careful preparations, he acted on the
rocky waves of his emotions.

The High Priest’s words hinted at the joy he felt in tormenting the weak. And worst of all,
that “unenlightened man” did not see any of the ugliness inside himself. His surface
consciousness did not at all think he was rubbing salt in the wound. He truly believed he
was showing his appreciation toward the person he confronted.

[...]

“Oh, come on,” said Aleister with no hint of emotion in his voice. “Why do you think I
challenged the Magic Gods alone when Othinus was defeated? Wait. Don’t tell me. Surely
you didn’t actually think a ‘human’ such as myself could be enraged by a simple stain in
a journal.”

“You...don’t mean...”

“I had to take the necessary parameters by force. That was all. It did get me laughed at by
some people I know, though.”

That was why he had not cared that he had lost.

He had only needed steal the Magic Gods’ parameters through direct contact and then
make it back alive.

-Shinyaku Toaru Majutsu no Index Volume 12 Epilogue


There were fresh wounds all over Coronzon’s mostly-naked body and they were seeping
blood.

Magic God Niang-Niang had done this.

But clashing head-on with that monster and only receiving these injuries was a testament
to Coronzon’s great power. Hamazura had no way of knowing, but Crowley had ended up
with half his body burned when he challenged the Magic Gods.

-Shinyaku Toaru Majutsu no Index Volume 22 Chapter 3 Part 10