Mephisto Sword Art

Hitotsume: Jigoku Nadegiril (地獄キルストローク, The First: Hell Killing Stroke): This is the first and often most powerful technique in Mephisto's arsenal as it is the simplest and the most effective. It is very similar to the Shinigami version of this, but adds more strength, speed and power behind the blade by removing most of the things that cause drag on the blade, such as air resistance and wasted energy moving the blade. This increases the cutting power of the blade expontientally.The blade moves at such a high rate of speed due to the reduced drag, and increased power behind the swing to easily slice through normal Hierros with ease. Mephisto Slices forward then caps the blade as the rate of the blades release creates such a precise cut of extreme force and power that most people aren't aware they have been cut until they see the blood dripping. If someone is trained in Swordsmanship, then they have an easier chance to blocking it, or a way to enhance their guard.

Futatsume: Jigoku (地獄, The Second: Hell ): Starting from a battojutsu draw stance, Mephisto draws and slashes in multiple angles then capping his blade. His blade moving faster than normal creates a vacuum of hellfire that shreds the enemy using the heat and flames from Mehpisto's Hellfire to burn through guards and to help heat the blade up to plasma like temperatures that makes it easier to bypass lots of normal guards. If someone can create a proper guard, counter or use a similar attack to deflect this one, they can counter it. Also, if they are fast enough to dodge, or if they are a skilled swordman they can counter this attack.

Jigoku Ryūkansen (龍巻閃,Hell Dragon Coiling Flash): Mephisto will most often used as a counterattack against a thrust or charge, one sidesteps a forward-moving opponent and moves past them. In doing so, one spins in a full circle, adding momentum and centrifugal force to the strength of the sword swing, which is then aimed at either the opponent's back or the back of the neck. This combined with the already insane power of Mephisto's normal drawing and cutting power can often slice an several opponents in half with little resistance on the blade. Even if the opponent managed to not be cut in half by this technique they would more than likely be sent flying just due to the sheer amount of pressure behind this simple but powerful technique.

These look fine to me. Approving.