See; Kei Uchiha's Training Log.
The user generates a fragment of 'pure' fire in between his hands. This single, although small, flame, or rather ember, then builds up, and stores, so much heat that it eventually turns yellow/white; bright enough to illuminate the blood under the skin of the user's hands. The user then 'grabs' and 'squashes' the flame in a single clenched fist in order to make the flame pop like a balloon and envelop his arm before the user then opens his hand in a flat palm with all fingers pressed together. The user's hand is then surrounded by a white hot source of fire chakra that spins directly around the user's hand like a small drill-top from which spawn two tendrils of fire that spin around the user's arm like a double helix; the faster the drill-like core spins around, the larger and more intense the tendrils become up to the point of forming mini-vortex around the user's arm.
Due to the level of shape manipulation required for this technique, it's very dangerous to learn and it will most likely, if not surely, leave the arm of use heavily scarred in unique patterns.
Even after having learned the technique it will still harm the user, every time its used, due to the intensity of the heat that is generated. However, a master of the technique can bypass these side-effects by building up a natural resistance of sorts, over time, as the scarred flesh becomes insensitive to heat; something that may very well be related to the fact that the burn-scars light up whenever the jutsu is used.
Deals a massive amount of focused damage; often lethal.
Has a great amount of piercing capability due to the searing hot core being shaped like a drill, meaning all force is first exerted through one small point.
Can be used offensively even while charging.
Can be charged up to three posts for maximum effect.
The amount of self-damage inflicted increases the longer that the user charges the technique.
Due to the level of shape manipulation required, the user needs to charge this move for a whole post during which the jutsu-using-arm cannot be used for anything else.
Charging for more than three posts causes the user's arm to completely blacken in burns due to the overburdening that occurs inside the chakra paths running through the arm, greatly harming the user while the resulting damage dealt to the target is immense. Another drawback of overcharging is that the arm in question cannot be used again for 24 hours or until being treated by a medic.