Last time in I was reborn in demon slayer as an Uchiha

As time went on Doma body was crumbling to the floor but his will to scar her before she die was keeping him alive for longer, Doma will was so strong and it did not budge as he truly wanted to do this.

It showed on his face that he would not accept death as long he hasn't achieved his goals.

For the first time in his life truth determination appear on Doma face as he truly wanted to do something and he was not going to back down.

His body started to deteriorate at a much slower speed giving Doma more time to achieve his goals and he would do it no matter what happen.

He had a crazy look on his face as half of his face was already purple and starting to deteriorate at speed visible to the named eye but he still looked very terrifying.

He then rush at her with a brand new fire on his eyes as he was going to wound this woman even if it's the last thing he does.

Now we continue where we left off. 

As Doma will to leave a scar on Shinobu's body was getting overwhelmingly strong. 

His body started to produce some antibodies to slow down the effect of the drugs. 

He was just delaying the inevitable because even if he is slowing it down, his body is not nullifying the poison or getting rid of it so his life is on a short timer that may end at anytime.

Doma however did not care about that small detail and the only thing in his mind was to be able to give her a scar before he die to show her his appreciation in his own twisted way.

As time went on Doma only had 3 finger in each hands as the other ones had crumpled under the effect of the poison and are now nothing more than ashes.

About 1/4 of his face was gone and the vision and his left eyes was completely gone, while his left leg had a hole in it.

The demon skin was now more purple than pale and even some purple veins were showing all throughout his face.

His body was getting destroyed but his will remained, he would achieved his goal even if it's the last thing he does.

As Doma was trying his hardest to hurt Shinobu, somewhere else in the castle A father and son were about to clash blade for the last time.

"Flame breathing First Form: Unknowing Fire"Rengoku said as he dashes towards his father at tremendous speeds, before unleashing a singular horizontal slash directed at Shinjuro neck for a quick decapitation.

"Flame breathing Fourth Form: Blooming Flame Undulations"Shinjuro said as he performs  multiple slash in a fluid circular motion to defend him from Rengoku incoming attacks.

The father and son duo continue to clash against his other and they seem to be about the same strength.

In term of speed Rengoku was slightly faster but it wasn't to noticeable,Rengoku flame like hair seem to have caught on fire as his hair started to act like an actual fire around his head.(A/N key word here being seemed, I don't want a bald Rengoku)

Shinjuro managed to slip in Rengoku defence before he kick him up in the sky, Shinjuro then perform the flame breathing Second Form: Rising Scorching Sun, as he unleashes an arcing vertical slash in an upwards motion trying to slice his son in half when he landed.

Rengoku however manage to get his balance midair before he used the flame breathing Third Form: Blazing Universe, as he performs an arcing downward vertical slash clashing his blade with his father once again.

He managed to block the hit that Shinjuro launched at him trying to cut him in half, he then kick Shinjuro in the face.

He used the momentum from the kick to get some distance between him and his opponent.

As soon as Rengoku landed he dashes at his opponent at full speed breaking the floor underneath him due to sheer speed and speed alone.

The sheer speed that he was moving at creating sonic booms that were very loud and very destructive and unlike how they were skillful before and did not destroy anything, his sudden burts of speed destroy everything around him as he was moving.

Shinjuro was now only just getting smack around like a ping-pong ball, his eyes never seem to stay on Rengoku for to long before he was launched somewhere far away.

"Flame breathing Fifth Form: Flame Tiger "Rengoku said as he dashes forth, bringing his sword into a high guard before he performed a series of sword slashes which take the form of a flaming tiger enveloping Rengoku body fully.

As the flame tiger roared and rush at Shinjuro, the upper moon didn't back out as he used the same technique as Kyujuro but only that his fore was blue as he was using his blood demon art to make it stronger.

As the blue and orange fire clashed it made a beautiful imagine appears as the fire seem to be colliding and pushing the other fire away.

The flames were trying to consume each other and they were very fierce, everything around them were getting burned to the heat as Rengoku was in the center of it, he started sweating but the weird Technique that he was using seem to be creating a protective layer around Rengoku protecting him from he tying burned.

It could not however protect him from the heat as Rengoku face was starting to sweat along and his veins started to budge.

The spark that we're created died to his clash with his fought stayed and continue to happen as their blade clashed until suddenly.

*Crack*

*Slash*

The sound of a slash and a sword breaking was heard as the flames died down and Rengoku and Shinjuro we're still standing.

Shinjuro head fell down before it hit the floor as he his body started to disappear as Rengoku body realised a lot of blood.

He got slashed pretty badly and if he didn't receive any help he would die bit he did not have the energy to move and so he passed out in a pool of his own blood.