After leaving the children to make it home on their own Y/n, Tanjiro, Nezuko, Zenitsu and Inosuke headed to a resting stop that a family that was saved by demon Slayers years ago set up so that passing Demon slayer could get a rest.

As the 3 boys got a sleeping mat the Slayer who doesn't request sleep leaned against the wall, as he did the old lady how lives here brought in a doctor to check over everyone, after checking the 3 all of them found out that all of them had broken ribs.

Tanjiro - 3 ribs broken
Zenitsu - 2 ribs broken
Inosuke - 4 ribs broken

Bur when the doc trued checking the Slayer he could due to his armour, Vega insured that the Slayer was 100% as he had been through a lot worse.

As the boys kept talking they began talking about how Zenitsu protected the box as it meant a lot to Tanjiro despite knowing there's a demon inside of it but as they did the box started making noise scaring Zenitsu. As the box door opened and Zenitsu began to scream again, but what looked like a fight was going to break out soon turned in to Zenitsu claiming that Tanjiro was travelling with a cute girl and he was jealous of him....which then leaned to Zenitsu chasing Nezuko but when Tanjiro tried stopping him he only then chased Tanjiro as well wanting to become friend, and soon Inosuke joined in, the Slayer sat and watched as Inosuke chased Tanjiro and Zenitsu chased Inosuke in a circle.

Slayer(mind) : "what is going on"

Vega : "I'm afraid I don't know as well Slayer"

As the Slayer watched he soon felt something lean against him, he looked to see Nezuko lending on his left arm. As he looked he saw Nezuko look up at him....

Slayer(mind) : "whatever at least she doesn't act like those dumbasses"

As time went on the Slayer began to feel weird for the first time in enos he began to fall sleep...

Timeskip

As the slayer was asleep next to Nezuko who was also sleeping, Tanjiro and the others had finally calmed down as they did.

Tanjiro : "hey...Vega right"

Vega : "hello Tanjiro is there something you wish to know"

Tanjiro : "well...I was wondering how the Slayer got those names"

Vega : "playing Slayer Testaments"

Just then a small hologram appeared that showed the Slayer fight endless waves of demon in hell.

In the first age, in the first battle, when the shadows first lengthened, one stood. Burned by the embers of Armageddon, his soul blistered by the fires of Hell and tainted beyond ascension, he chose the path of perpetual torment. In his ravenous hatred he found no peace; and with boiling blood he scoured the Umbral Plains seeking vengeance against the dark lords who had wronged him. He wore the crown of the Night Sentinels, and those that tasted the bite of his sword named him... the Doom Slayer.

Tempered by the fires of Hell, his iron will remained steadfast through the passage that preys upon the weak. For he alone was the Hell Walker, the Unchained Predator, who sought retribution in all quarters, dark and light, fire and ice, in the beginning and the end, and he hunted the slaves of Doom with barbarous cruelty; for he passed through the divide as none but demon had before.

And in his conquest against the blackened souls of the doomed, his prowess was shown. In his crusade, the seraphim bestowed upon him terrible power and speed, and with his might he crushed the obsidian pillars of the Blood Temples. He set forth without pity upon the beasts of the nine circles. Unbreakable, incorruptible, unyielding, the Doom Slayer sought to end the dominion of the dark realm.

The age of his reckoning was uncounted. The scribes carved his name deep in the tablets of Hell across eons, and each battle etched terror in the hearts of the demons. They knew he would come, as he always had, as he always will, to feast on the blood of the wicked. For he alone could draw strength from his fallen foes, and ever his power grew, swift and unrelenting.

None could stand before the horde but the Doom Slayer. Despair spread before him like a plague, striking fear into the shadow-dwellers, driving them to deeper and darker pits. But from the depths of the abyss rose The Great One, a champion mightier than all who had come before. The Titan, of immeasurable power and ferocity. He strode upon the plain and faced the Doom Slayer, and a mighty battle was fought on the desolate plains. The Titan fought with the fury of the countless that had fallen at the Doom Slayer's hand, but there fell the Titan, and in his defeat the shadow horde were routed.

And in his terrible rancor between worlds and through time, the Hell Walker found the wretch who shall not be named, but in his heresy was loyal to his evil cause. The wretch adorned the Doom Slayer in a mighty armor, wrought in the forges of Hell, impenetrable and unyielding. With sword and shield of adamantine strength, the Doom Slayer set to banishing all that were left unbroken by his savagery to the void.

Yet as the mighty Titan fell and dread engulfed the armies of Doom, the demon priests of the Blood Temples laid a trap to capture this scourge of Hell. Insatiable, even by the vanquishing of the Great One, the Hell Walker sought prey in the tombs of the Blood Keep. And blinded by his fervor, the lure drew him in. The priests brought down the temple upon the Doom Slayer, and in his defeat entombed him in the cursed sarcophagus. The mark of the Doom Slayer was burned upon his crypt, a warning to all of Hell that the terror within must never be freed. There he lies still, and ever more, in silent suffering....