Can I at least say my last words

The constant dinging roused him from his slumber. He turned to the side, a groan slipping out from his parted lips.

Sluggishly, he stretched his hand out, his eyes heavy-lidded with sleep.

Tap, tap.

His palm brushed over his side, but his brain hardly registered the smooth fabric under him.

He turned over from his stomach to his back, shifting to find the most comfortable position.

He paused.

"Wait, fabric!"

His eyes snapped open, and he jumped off the bed. His breath was ragged, coming out in pants, and his heartbeat quickened.

As he surveyed the unfamiliar place he found himself in, he asked with wide eyes, "What—where am I?"

A blur of scenes flashed through his mind, but when he tried to think about it, a sharp pain, like a knife stab, shot through his head.

"Arrgh!"

He groaned again, dropping to the bed as he held his head with both hands.

He stayed in that position, his hands gripping his head, waiting until the pain subsided.

As quickly as the pain came, it disappeared as if it had never been there.

After a few minutes, confirming it was gone, he slowly took his hands off his head.

He paused.

"Okay, nothing," he concluded.

"I wonder what those images were—" but he cut it short, fearing that if he thought about the past again, the terrible pain would reappear.

Shaking his head, he thought, "It doesn't matter," trying to kill off the curiosity that itched to know.

"Or can I… just try again?"

"Yes, maybe that was just a coincidence. The pain should—could have been a mistake," his tone became low at the end, stammering slightly as he couldn't find the motivation to try again.

His eyebrow twitched as he debated giving in to his urges; it was like a feather scratching the surface of his heart.

Throwing his head back, he took in the white-painted ceiling in the quietness.

"Haa."

For the nth time, he sighed, shattering the silence that had descended.

"—You know what, it doesn't matter," he repeated again, emphasizing "doesn't matter."

He pursed his lips in dissatisfaction.

He hated the feeling of not knowing something, especially when it was within his grasp.

If only he could try harder, but he hated pain.

Since he could do nothing about it, he decided to leave the thinking for next time.

With this, he sat up from the bed, pushed himself off, and took baby steps.

He winced, massaging the sides of his head, as if he could feel the phantom pain popping back up.

He wobbled off the bed, making a beeline to a door. His surroundings blurred for a moment.

Slamming the door open, the scene changed—from messy but warm to clean and cold. Floor-to-ceiling white tiles encircled the room.

Ding ding.

He could hear an annoying ringing in his head that kept getting louder.

'Make it stop!'

His legs gave out, sending him crashing to the floor. Pain shot up from his knees, but it was drowned out.

He slammed his head, bashing it against the floor repeatedly. 'Arrgh!'

His large hands clawed at the icy tiles, his body spasming.

Unknown to him, faint blue spiral tattoos lit up around his body, pulsing in response to something unknown.

His back hunched over, his knees on the floor. Cradling his head, his teeth sunk into his lips, drawing blood.

Underneath the ringing was a mechanical glitching.

It choked out: 

[Choosing the host…] 

[Host meets all the criteria.]

In response, the faint blue runic tattoos grew brighter and pulsed faster in resistance.

The mechanical sound paused, disappearing, only to return more violently, struggling to succeed.

[Binding the host to the system…]

Trails of red liquid flowed down the man's ears and nose, dripping onto the white tiles, staining them red.

The strain was too much for the man to bear; he succumbed, fainting.

On the other hand, regardless of the man's physical state, two forces kept battling within his body—one a system, and the other a mysterious power.

The system struggled, desperately trying to grasp control over the body, while the other struck again, repelling it, causing the system to retreat back to the confines of the mind, losing hard-won ground.

Frustrated, the system started integration prematurely.

[Commencing integration…]

[1, 2, 5…]

Another intangible force swept through the body, from the feet to the head—where the invader lay.

[…70%, 72, 78…]

The force blocked off all its escape routes, cornering it, gradually encroaching into its corroded space. Everywhere it passed turned vibrant again.

[…85, 88,…]

In a last-ditch effort, the system struck, clumsily stretching out its tentacles, blindly striking empty spots around it, panicking.

'I haven't ticked off half the things on my bucket list yet!'

[89, 90, 91…]

The almost-full percentage alerted it. While keeping the mysterious power at bay, its mind rotated.

It cackled inwardly, feeling clever, when a blur passed before it, followed by blinding pain.

Half of its body lay squirming by the side.

[92, 93…]

[Brother! Brother Blue!] the system stammered out.

[I didn't know you were here. If I knew, I wouldn't have come, even if I were given a thousand livers!] it swore.

[If you allow me to leave, I'll roll out immediately—] it added hurriedly, [without being asked, of course.]

[94, 95]

[I can't make my big brother say too much,] it rambled on, trying to delay the time for the percentage to fill quickly, while thinking, 

'Once I fully integrate with this body, it'll be me in charge, then we'll see who is truly the big brother.'

[96…]

Similarly, the blue force allowed the system to stall. It had taken up a lot of energy with each strike. It played along, charging up with the goal to deliver a killing blow and end this once and for all.

[Big brother, you really look good, blue and all—not like me, green,] 

'And I'm sure you'll equally taste delicious,' it added silently, licking its non-existent lips.

[97…]

[Can I at least say my last words?]

[98…]

[You're a failure of a guardian, and even in death, you'll always be.]

[99…]

The system struck, enraged, with the mysterious force following a second slower.