Bleach 521: Ichigo vs Shizen.

Shizen stands straight with a smile on her face, her hands held out wide to either side.

Shizen: Bankai! Yoi tsuki no okoku! (Realm of the moon God)

Her sword that is planted in the ground 50 feet behind her glows and slowly begins to disintegrate. From where the blade is planted in the ground, two lines spread out to either side and quickly form a large circle around Ichigo and Shizen.
Shizen's sword begins to form itself back together in Shizen's hand.

Shizen: welcome to the realm of the moon god.

Ichigo looks around but see's nothing else has changed. He looks at Shizen for a moment and then flash steps. He disappears and immediately reappears exactly where he was standing before.
A look of surprise crosses his face as he finds himself back where he started.
Shizen looks at him smiling and says mockingly.

Shizen: You can try again if you like, I'm happy to wait.

Ichigo tries once more, and then again and again. Each time he disappears and reappears back where he started.
Ichigo stops and looks towards Shizen.

Ichigo: what is this?

Shizen: are you now asking for my help? How pitiful! This is my bankai Yoi tsuki no okoku, the realm of the moon god.

Ichigo:...

Shizen: this realm is split off from everything else. I am god in this realm and I control it!

Ichigo:...

Shizen: do you understand? Can you comprehend?! You wanted to move and I wished you to stay right there, so the realm adjusted itself so that you ended right where you started off.

Aizen: I see...what a wonderful bankai.

Shizen looks over to see Aizen looking at her with his own mocking smile. She smiles back in response.

Shizen: you can mock me all you like but my ability far surpasses your own.

Aizen: hehe, I am afraid you are very much mistaken my dear, Kyoka Suigetsu did not have so many flaws, and you have not yet seen my bankai either I believe ...

Shizen: hmph.

Aizen: I wonder though, what would happen if you faced multiple foes? What if someone attacked you from outside your...little realm.

Shizen: ha, well if you have any more little tricks left up your sleeve you're more than welcome to try.

Aizen: No, I don't think I need to do any such thing. 'Split off from everything else' was what you said wasn't it? I would estimate that anything other than what you wish cannot cross through...so for the present situation I would assume anything other than air or sound?

Shizen scowls and turns back to look at Ichigo, her mocking smile returns as she looks at him.

Shizen: so Kurosaki Ichigo, would you like to try anything else? Or shall I finish this off right now?!

Aizen: (Now Kurosaki Ichigo, let's see how much you've really grown)

Ichigo raises his sword arm slowly until his sword is pointed straight up. He slashes it down casually with no real energy force. His voice is quiet as he speaks.
Ichigo: Getsuga Tenshou.

The black crescent moon of reiatsu arcs its way towards Shizen. She laughs as it narrowly misses and flies past her. As it reaches the boundary line directly behind her it just vanishes without a trace.

Shizen: That was pathetic! Is that what you call an attack or have you just given up already?!

Aizen: (no, that wasn't an attack at all)

Ichigo:…Getsuga Tenshou!

Ichigo lashes out, this time so fast that his swing cannot even be seen. The black arc of reiatsu is upon Shizen almost instantly.

Aizen: (that wasn't an attack either, but how much have you learned Kurosaki Ichigo?)

Shizen stands relaxed and still as the Reiatsu is about to envelope her, she smiles and suddenly the reiatsu's movement has reversed and it's now storming towards Ichigo. Ichigo jumps sideways to avoid it, as he lands he finds himself back in the same spot he was. The getsuga tenshou hits him head on throwing up a cloud of dust as it explodes.

Shizen: hah, you're speed is pretty good but nowhere near fast enough to catch me off guard.

Ichigo appears directly behind her his sword swinging to split her waist into two. As he strikes her image wavers and vanishes, as the cloud of dust settles we can see she is now standing where Ichigo was before.

Shizen: Pathetic, it should be obvious even to you that I don't have to see you to act. At this proximity I can clearly feel your reiatsu and sense when you're about to do something.

Ichigo: …

Shizen: You do realise it don't you? That I'm playing with you? Just like a cat plays with a mouse before it devours it? If I had wanted, I could have kept you grounded to this very spot (she points down), I'm just giving you the opportunity to understand how helpless you are against me, even if you released your bankai you wouldn't be able to accomplish anything!

Ichigo plants his sword into the ground in front of him and lets go of it. He looks at Shizen.

Ichigo: and what if I decide to just stand here and let this stalemate play out. You won't be able to keep up your Bankai forever, you are slowly getting weaker and weaker giving me the advantage.

Shizen: Getting weaker? Huh, how pitiful you are, as if you have the luxury of waiting that long. We Zero squad aren't as weak as the captains of your soul society. My bankai solely specialises in capture and detainment. Do you understand Kurosaki Ichigo! I can either subdue someone in this realm or indefinitely contain them. There's is nothing they can do to escape.

Shizens mocking smile changes to an angry glare

Shizen: That being said, for scum like you, what makes you think I have any intention leaving it that long?!

Shizen appears right behind Ichigo slashing out at him. Ichigo immediately jumps forward away from her whilst half spinning so he's facing her. His jump takes him no further away as he looks at Shizens mocking smile as her sword arcs down at him and strikes him where his neck meets his shoulder.
Shizens face takes on a shocked look as her sword strikes Ichigo but fails to slice through him. Her eyes focus on Ichigo's arm to see that he has grabbed her hand and sword hilt once more stopping them in place.

Ichigo: You control this realm but you don't control me.

You see Aizen in the background with a telling smile on his face.

Ichigo: You couldn't stop me from attacking or moving, you couldn't even stop my attack with your ability.

Shizen struggles to release herself from Ichigo's grip but is unable to

Ichigo: Which means you can't control the people trapped within it but just this place itself. Now that we're connected, however much you move this place around it won't make a difference.

Shizen: pah, what of it, you'll have to let go of me sooner or later.

Ichigo's sword suddenly disappears from behind him and is now all the way at the other end of the circle. Ichigo turns his head slightly to see it move.

Ichigo:…I never had any intention of using my sword.

He suddenly releases his reiatsu, the air vibrating around him shimmers as if waves of heat are being released from him. He raises his right arm and reiatsu flows out of it looking like flames. You can see beads of sweat already forming across Shizen's forehead.

Ichigo: *Rage of the swordless Slice*

He strikes Shizen across the collar bone with the edge of his hand. She crumples towards the ground, unconscious, as his hand connects. Ichigo lets go of her hand letting her collapse completely as the white lines of the boundary disappear.

Aizen: I would clap if only I were able to Kurosaki Ichigo.

Ichigo:…

Aizen: Baiting her by parting with your sword, feigning escape so that she'd pull you back into her strike range and coincidentally put her within your reach as well. What a great little schemer you've become.

Ichigo: ...

Aizen: However I must admit, I was a little disappointed. That took a little longer than I had anticipated… maybe I was expecting a little too-

Ichigo: I had no intention of killing her.

Aizen: …Still not willing to take the decisive blow, I'm a little surprised.

Ichigo: No, I still have questions that need answering… by her and by you.

Bleach 522: True Intentions