Ultimate Defence: Black Gate

This is a difficult jōnin-level technique created by Kama Uchiha and, according to him, his strongest defence.

Creation
Kama studied the Rashōmon technique in an attempt to find and possess an impenetrable defence in his arsenal, and was quite disappointed when several of them were reduced to nothingness by a single Tailed Beast Ball. Using his studies on the aforementioned technique, Kama formed this technique which would transcend the rashomon and be a defence like no other.

Usage
Kama forms a single handseal and bites his thumb, slamming palm on the ground. Several markings quickly emanate the area, and then, after a brief puff of smoke, a long, black gate will appear, stretching 40m in length, 20m in height and 5m in width. This gate's defensive power is unreal, and it was able to take hits from several Tailed Beast Balls unscathed, with the exception of a few minor dents, though Kama made a simple gesture and the scratches disappeared, signifying that the gate can regenerate.

Drawback
This technique, however, has an extremely dangerous weakness; it can only protect from incoming attacks infront, and is unable to defend a ninja backwards. The technique was also able to be countered by a target from above, though Kama countered that by manipulating the gate to potrude adamantine spikes that impail anyone above.