What if tanjiro got the carnage symbiote?

The first step

Tanjiro makes it to tamayo's house and walks in.
Tamayo;Ah,Tanjiro,your back.
Tanjiro:Yes.I have the blood of a marechi and a demon.Here you go.
Tanjiro pulls out two devices.Tamayo takes them and holds them in one hand.
Tamayo:Now for the last thing,a piece of your symbiote.
A small blob of the symbiote comes out and Tanjiro hands it to her,Tamayo holds it in her other hand.
Tamayo:Thank you,now follow me.
Tanjiro and Tamayo walk into a room,they see Yushiro setting up lab equipment.Tamayo goes to his side and lays the three substances down. She grabs a cylinder and puts the three substances into it.She starts to spin it around, and the substances already mix.She pours them down a thin tube as they mix together even more.
Tamayo:Fascinating.
The mixture goes through the tubes into a beaker as the trio beholds it.It's a complete new liquid,it isn't red,but black.Tamayo grabs the beaker and walks to tanjiro.
Tamayo:Judging from what you told me of the symbiote it should be able to merge with this as it merged with your blood before.
Tanjiro bites his palm as it opens up.He holds it out as Tamayo carefully and slowly pours it into the wound.As the liquid flows through Tanjiro's bloodstream,both he and the symbiote are overcome with a feeling.An unfamiliar feeling courses through them as the liquid mixes with Tanjiro's altered blood,the fluids mix as the symbiote emerges all over Tanjiro's body.No longer completely red,the symbiote is now wrapped around and mixed with the black liquid.
Carnage:You know,I was thinking of how this would feel,and I have to say...

Carnage:This is much more different than anything I expected.
Tamayo:Incredible,a complete synthesis and mixture.
Carnage beholds himself and looks out of the house.
Carnage:Alright,let's test this out.
Tamayo:Where are you headed?
Tanjiro:To a mountain,a friend of mine was heading there to see about some demons that he heard were there.
Tamayo grabs one of the devices and hands it to carnage.
Tamayo:Use this.Be safe on your journey.
Carnage:Yeah...and thanks.
Carnage runs out of the house at high speeds, in minutes,he arrives at the foot of the mountain.The symbiote sinks away as tanjiro prowls around,eventually he sees Zenitsu.
Zenitsu:Oh!You got here quicker than I thought you would.
Tanjiro:I'm very fast.
Tanjiro and Zenitsu walk up the mountain. They roam across its grounds and see nothing so far.
Tanjiro:See anything?
Zenitsu:No,you?
Tanjiro:No.Tell me,why are we searching during the day?
Zenitsu:It's considered easier to find a demon whose options are limited.Wherever the demons are,it's most likely some cave or dark spot.
Tanjiro:Hmm,alright then.
Tanjiro walks to a large walk and relaxes on it.
Zenitsu:What are you doing?
Tanjiro:I'll just wait until the demons show themselves.
Zenitsu:O-oh!Are you sure?Demons are no slouch any under circumstance,but at night they're at full strength!
Tanjiro looks directly into Zenitsu's eyes.But strangely,Zenitsu doesn't feel threatened.In fact,it's the opposite,he feels assured,and confident.He walks to Tanjiro's side and relaxes on the rock alongside him.
Tanjiro:I'm going to be honest with you.I'm confident that against the two of us,no one, demon or human,even at their full power, stands the slightest chance.
Zenitsu:You-you really think so?
Tanjiro nods.Zenitsu smiles shyly as he and Tanjiro merely wait.And eventually-

Night time has fallen.Tanjiro and Zenitsu ready themselves and roam the night.Suddenly,a demon slayer comes out of the bushes.
Zenitsu:Huh?Oh,look Tanjiro,it's-
Suddenly the demons slayer pulls his sword back and attempts to swing at Zenitsu,but Tanjiro grabs him and pulls him backwards.
Demon slayer:I'm sorry!I'm being controlled! You need to run!
Tanjiro looks around the slayer's body and sees thin but strong threads.Tanjiro grabs and preps his cleaver.Tanjiro charges at the threads and swiftly cuts them.The slayer freely falls to the ground.
Demon slayer:Th-thank you!But there's more! Over there!
The slayer points to behind a bush.The two walk through it to see an entire army of demon slayers being held up by threads.
Demon slayers:RUN!
Tanjiro and Zenitsu prepare themselves,but suddenly,the threads jerk and turn,causing the limbs and heads of the slayer's to break and snap.Zenitsu watches in terror as Tanjiro grows angry.He watches the corpses of the slayers as Zenitsu is overcome with a pressure.
Tanjiro takes a breath as long red and black blades extend off of the back of his arms.
Tanjiro:Darkness breathing,3rd form scream!
Tanjiro leaps at the threads,and one by one,he cuts them with strong slashes.Zenistus gazes at Tanjiro in amazement,but also fear.
Zenitsu:I'm not sure who I'm more scared of, this demon,or Tanjiro.
Suddenly,multiple tendrils emerge form Tanjiro's body as they each grab a demon slayer.One by one,their limbs are twisted back and healed.One by one,the demon slayers stand back up,amazed by their revival.The slayers all look at Tanjiro and simultaneously say-
Demon slayers:THANK YOU!
Tanjiro:You all need to leave,now!But before you do,don't tell anyone else what happened here.
The slayers agree and descend down the mountain.
Zenitsu:H-how did you do that?!You can't be a demon since you were in the sun,but those tendrils..,
Tanjiro:Don't worry about it.Just know that...I'm here to help you.
Zenitsu:If you say so.
???:HAHAHAHAHAHAHAHAHAHAHAHA!
Tanjiro and Zenitsu look up to see a inosuke body slam a demon right in front of them from the sky.Inosuke pulls his blades out and swiftly beheads the demon.
Inosuke:Take that!Huh...Kenpachiro?Dodotsuu?
Zenitsu:HEY!
Inosuke:What are my favorite insubordinate doing here?
Zenitsu:WE DON'T WORK FOR YOU!
Tanjiro(thinking):Things couldn't have gotten better.
Tanjiro was very confident.Inosuke and Zenitsu were strong on their own.But together with him?They're unstoppable.
Tanjiro:Hey.
Zenitsu and inosuke quit their arguing and look to Tanjiro.
Tanjiro:Let's keep traversing the mountain. With the three of us,we shouldn't have any trouble with the demons here.
Inosuke:HEHE!I like you kenpiro!That's why you're my favorite!
Inosuke triumphantly walks along the mountain as tanjiro and Zenitsu "follow".