human
Garfiel:  “—Oooooo! !” A howling voice accompanied the ground cratering as Garfiel, on all fours, transformed. His bones audibly creaked as his body swelled, and he bared his fangs as golden fur appeared all across his skin. Having turned into a ferocious, mindless beast for the purpose of killing Subaru Natsuki, Garfiel roared.
gpt
Garfiel:  “Gaaaaaaa—! !”
human
Narrator:  This was a decision to kill. Garfiel deemed he had no choice but to kill Subaru. Subaru could not be stopped short of killing him. The last ten years had left Garfiel unable to sheathe his fangs. Hence, Garfiel transformed as a last resort, for the sake of taking a life. —Turning into a mindless beast so that he would not avert his eyes at the critical moment.
gpt
Narrator:  Not wanting to slay his foe, to thrust his claws through his opponent, was kindness. The decision to use his body to protect the hearts of those around him, to protect the Sanctuary, was kindness. But making excuses for supposedly unclouded wishes and feelings in order to kill someone who couldn’t be left alive, averting his eyes to his own actions, and going as far as to stop thinking at all—that was not kindness. It was weakness. And Subaru Natsuki did not hesitate to take advantage of that weakness.
human
Subaru:  “I’m counting on you, body of mine. Don’t break down on me when we’re inside the ring!” The transfigured Garfiel bent all four limbs, widening his fangs as if to bite Subaru with them. Instantly, Subaru pictured a gate above his navel that was connected to the very center of his body and chanted.
gpt
Subaru:  “—Shamaaaaaaak! !” Just before the great tiger leaped forth, Subaru shouted with all his spirit, and the world shouted back.
human
Narrator:  An incomprehensible darkness explosively spewed forth, swallowing the fiendish beast, who was extending his sharp claws whole. Those claws, which should surely have shaved away Subaru’s life, never reached their target; the fiendish beast’s bloodlust was erased somewhere in that abyss. The next moment—
gpt
Subaru:  “—Ah.” Subaru realized that a fateful impact had destroyed something in the deepest part of his body. He’d abused the Gate he’d been told not to use. He’d used the magic that he’d been forbidden from using. He’d gone against the warnings of his personal healer, the greatest healer in the kingdom. The cost of betraying those words might have been to never be able to use magic again. The Gate that had been at Subaru’s core collapsed. Violently, chaotically, oblivion clawed at his mind.
human
Subaru:  “Thanks.” The cord he had relied on so many times to date had been cut. To this feeling of losing something he could never regain, Subaru spoke words of parting. The magic he had relied upon several times over had finally had enough of him. It could not be helped. But he was grateful nonetheless. With gratitude in his chest, he took a powerful step forward.
gpt
Narrator:  His goal of landing a single blow had been met.