Notes:

Namco deserves a 2nd rep just as much as Capcom AND we could use another villain character in the game… so here's Nightmare! His main outfit would be the design in this image (from SC5) and two of his alternate costumes would be of the past wielder of Soul Edge, Siegfried: one in his armor (from SC4) and one of him partially corrupted by Soul Edge (from SC2)

Standard-B "Stance Swing" = A vertical sword sweep that hits above as well as in front, and goes all the way around when done in the air. When done on the ground, pressing in a direction during the attack puts Nightmare in one of three stances that can lead to other unique attacks.
Side-B "Bloody Jade Impact" = A forward dash with Nightmare's demonic arm. Holding B turns the move from a ramming attack that knocks the foe sideways into a grab and energy blast that launches them upward.
Up-B "Soul Slash" = A jump and a front-flip slash, hitting a wide radius and unleashing an energy blast upon landing on the ground. Has more vertical movement than horizontal.
Down-B "Soul Wave" = An energy blast all around Nightmare that damages opponents in a wide radius but does not make them flinch. With good timing, Nightmare can avoid flinching from an incoming attack or even deflect projectiles with this move. Can also be done from any stance.