Heru no Juin - (Hell's Curse Mark)

Seal Name: Heru no Juin - (Hell's Curse Mark)
Rank: S
Appearance:
Location of Seal: Left Shoulder
Positive Effects: When activated, it allows dead souls to peer through and emerge from his body. They are always attached and look to be coming out of his skin. These souls appear as if they were made of a blackish, oil-like liquid and when attacked, the souls regenerate themselves. However, their nails are harder than carbon nanotubes and because of all the souls peering out of his body, they have a complete 360 degree view and will stop at nothing to protect him. Should Battei be knocked out, the souls will still protect hm but will emerge in large numbers because he is not conscious to keep them inside.
Negative Effects: When activated, the seal eats away at the user's mind and personality, driving them to madness if used too long. It also takes quite a toll on their body, since they are being mutated by the seal and Battei is unable to perform partial transformations. As for the souls, fire is their weakness. As being suppressed in hell by fire, fire attacks will burn the souls, causing the soul to die and no longer exist. However, lightning based attacks also do wonders as the electricity will travel down the soul towards Battei, who is attached to them.
Transformation Effect: When activated, the seal will seep into his skin where it will vanish from the surface. As it does this, the seal will spread beneath his skin like souls trying to escape his body. While activated, his skin has turned dark-gray and his hair grew while turning dark blue. And like all Cursed Seals, the user receives increased chakra levels and physical capabilities when the seal is active.

Spoiler:

Seal Info: Volo, brother of Kyouken Shikyo, was a strong and powerful shinigami. As he delivered the souls of the evil to the underworld, he began thinking of a way in which he could harness their power. Volo studied Orochimaru's Curse Seals, particularly the Heaven Seal until he created his own. The three tomoe of the Heaven Mark are viewed to be rotating in a counter-clockwise motion while his own Curse Mark rotates in the opposite direction. This represents how the Hell Mark is the counterpart to the Heaven Mark. Also, unlike any seal before hand, the Hell Mark only has one stage. As to not disturb the souls of those who have been delivered to heaven, Volo focused only on using the souls of Hell, thus naming it "Hell's Curse Mark". Unfortunately, Volo could not use it on himself as the Curse Mark could only be used on a recently dead human and would bring them back from the dead. After falling in love with a human, Volo shared with her the information of the Curse Mark and where it was kept. The Curse Mark itself was stored within a scroll and kept within the highest guarded library of the Anbu Black Ops. Labeled as a forbidden resurrection jutsu, no one but Volo and his wife knew of it's greater power. After Volo died, his wife became the only one knowing of it's true existence. And on the night of his death, Volo's one and only heir was born. Kyo, the half Shinigami, half human, died only a few nights later. Swarmed with grief, his mother broke into the Anbu base and stoll the hidden scroll, only to use it on Kyo's limp body. Unable to control the instant activation of the curse mark, the souls killed many who tried to kill the newly reborn baby. His mother, realizing her mistake, tried to take back her mistake but also suffered the same fate as those that tried to kill him.

Approved unless said otherwise.