I'm gonna be the only Hashira with a Bankai

Filler till Tanjiro Recovers

Shika's POV
After the battle between the weakest of the upper moons, Tanjiro fell unconscious, Tengen survived with only missing a eye and a few fingers(precisely his index, middle, and ring on his left arm), Zenitsu will wake up tomorrow, Inosuke will be fine because he's built different, Moya is exhausted, Ryōiki is fine by the way. After getting to the butterfly estate along with the others I decided to get some rest to, since I fought my hardest against Gyuutaro, but a little pissed Daki knocked me out. But atleast I got some training out of it, I've been training to use a regular katana but not a sword shaped weirdly like Zangetsu, so I shouldn't really be complaining. As expected I got another secret reward for assisting in killing upper moon 6, though I'm on par with high demon slayers, I'm only Hashira level with the boost of FC now. Plus I've decided to train with Ryōiki during this period before Tanjiro wakes up since I figured my breathing style would be derived from Thunder Breathing, plus there's no matter that UM1 with mostly likely question my attacks when I use the Getsuga Tenshou since his style is similar to mine. All I can do is rest for now and wait for tomorrow for my training to begin with this successor of Thunder Breathing.

Timeskip to the next day
I had asked for Ryōiki to spar with me as in training since I would like to take this opportunity to learn about one of the main breathing styles. Both of us grabbed a shinai for us to spar with and I asked that both of us be able to use breathing styles to, it was all apart of my plan, to see which style is superior. As the battle began she immediately used the first form of Thunder Breathing, I could only react by throwing my blade towards her before she could even leave her position. I her the sound of the shinai clashing together but she still disappeared, so I disappeared as well, leaving both of us not hitting each other and both of us in the other position, we faced each other and ran towards one another simultaneously. Our attacks had no affect as we kept clashing, I made one strong swing and she blocked it causing both of our shinai to break simultaneously. I initially wanted the fight to last longer so I went for a roundhouse kick for her head, not only did she s block my attack but caught my leg and slammed me across the floor, I got back up and both of us turned this sword fight into a hand to hand combat spar but I realized I was outmatched 15 seconds in. Ryōiki may seem lazy but she can tank a lot of my hits and be unfazed my most of them, plus she's more powerful than me. A minute in I'm nearly exhausted and my body is aching, but even I can tell that she isn't even using half of her power so I used Observe on her, trying to see how powerful she is.

Name: Ryōiki Hakumai
Level: 130
Occupation: Demon Slayer
Rank: Hinoe
Title: True Successor of Thunder Breathing
HP: 4,900
MP: 4,100
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Strength: 300 Vitality: 350
Agility: 180 Breathing: 200
Sense: 100 Endurance: 340
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Current Skills
Passive Skills
Power adjuster[Lv:Max]
Enhanced Sense[Lv:Max]
Constant TCB[Lv:Max]

Active Skills
TCB[Lv:Max]
Thunder Breathing[Lv:Max]
TB 1st Form[Lv:Max]
TB 2nd Form[Lv:Max]
TB 3rd Form[Lv:Max]
TB 4th Form[Lv:Max]
TB 5th Form[Lv:Max]
TB 6th Form[Lv:Max]

Items
Nichirin Sword
Charm

So this is the power of a high rank slayer,I've lost this battle completing. I attempt to block one of her hits but instead I got sent flying and hit my head against the wall.

Ryōiki's POV
Oh shit I just beat a pillar, I knocked him out but I didn't expect to, I'd thought he would win since he's much faster than me but those hits barely fazed me, I think I should've held back more. I picked him up and headed towards an open room to put him, I throw him on top of the bed and proceeded to go to my own room I've been staying in since the upper moon incident in the red light district. I'll forever hate that pillar for making me wear makeup, glad he's retired anyway, I can take his spot when I finally kill 15 more demons and become a pillar. Though I can't believe he dodged my first form point blank, his reaction speed is higher than mine, I could've swore my sword almost hit him but he was already behind me before I could stop. Well I guess it's time to head out, staying here won't get me anywhere plus I know I'm gonna be bothered by my crow the second I take time to relax, maybe I'll go find that Geezer of a uncle and get some guidance.

Shika's POV
I was in my Zanpakuto's world with Old man and Hollow Zangetsu.

"Shika it's time you start training for your Bankai after witnessing the power of the Upper Moons and eventually Muzan." said Old Man Zangetsu.

"I know your suppressing my power and I know I'm not ready to gain access to all of it at once so let's do this thing so I can face a upper moon singlehandedly. I already know how to materialize you into the physical world, I can do it again." I responded.

"So you caught on to you unconsciously materializing me?" asked Old Man Zangetsu.

"I've known ever since I needed to summon Zangetsu, so let's get to training." I answered.