Dark chidori

The Chidori manafests the Lightning Chakra in the air, but under the influence of the curse mark its power is amplifieyd and the lightning is turned black.

This can only be done in second stage because without it the curse mark doesn't have enough influence over the ninja useing chidori.

While in second stage the black chidori will peel through 5 thick steel walls and dent the 6th, because of the massive amount of chakra it uses. That can also be a down fall using twice as much chakra this should ONLY be used as a last resort..