Moe ninja girls: The Awakening Of The New Evil (Winter's Memories)

The Pathway DownHill (What makes him the second strongest of all) (10)

Yasu: This is nice!

Kihiro: Let's start killing each other.

Kihiro landed on her foot creating some distance between her and Yasu.

....

Ryuu: I feel dizzy still.

The three are now okay, but still with several aftershocks from what happened.

They are composing themselves as Kihiro buys time for them.

Haruto: We need to get in battle fast!

Airi: Then, compose yourselves!

Yasu looks at the four of them. He wants to deal with them earlier. However, seeing that Kihiro is a huge hindrance.

Kihiro: You will not hurt those kids.

Yasu: Oh no, I will. After I deal with you.

He then cracks his fingers and summons a spear made out of the shadows from his body.

Kihiro: Well then,

The forbidden Jutsu/Form usually gives the host another new set of abilities, just like how Yasu gained the super strength ability and unlimited shadows.

However, for Kihiro, it is different.

Manipulation of those weaker than her, string control, Fire Jutsu, and The ability to summon things, all them remained the same.

However, due to her using the dark energy within her body, all those abilities are now embedded with black energies, further strengthening them and adding several anti-regeneration properties.

She promptly raised her hand up and in the next second, several big swords manifested out of nowhere above her hand, with the blade having anti-regenerative effects.

Yasu: Anti-regenerative effects? What a drag...

Then, in a single swing, she launched towards Yasu.

He has no choice but to dodge, otherwise he won't be able to heal. He jumped up, and from above, summoning a shadow foothold underneath his feet, he leaned down and dashed towards her.

Kihiro: Forbidden Jutsu: Blood Strings.

To defend herself, she threw her hands outwards from her chest and launched a barrage of red strings all around her. The incoming Yasu had to teleport through the incoming string to dodge it. Then once through, he held his spear tightly and swung widely towards Kihiro's direction, the slash leaving several shadow residues, similar to a flame dancing.

Kihiro summoned a set of overlapping strings that formed a thick shield. The blade of his spear clanged against Kihiro's iron set of strings. In the next second, the overlapping strings exploded, destroying Yasu's shadow spear.

Both of them jumped back from the explosion. 

Yasu: The fifth and the second pillars are on the same level?

Kihiro: That must mean you're weak then. 

Yasu: What a trash-talker you are. Then, 

The next second, the shadows dispersed from his body, and then, formed a huge flood within the whole space, engulfing the ground in shadows.

Kihiro used her levitation jutsu on the four of them, that way they wouldn't have to exert energy on levitating, and only need to summon the energy for summoning footholds to step on

...

Just before they entered the wormhole, Kihiro warned the four of them of one thing. 

"I'm significantly weaker than you, Ryuu, I can't fight the four of you, and so I can't defeat Yasu... However still, you can't defeat Yasu by yourselves. You need me. Do not die while Yasu is still alive as I can't kill him, he's far too superior. You four are the key to defeating him. I am only here to assist you and buy time if ever you need so. I'll be a tank if ever you need a frontline. I will do everything in my power to keep you alive, so you can kill him."