Kasumi and Ayane vs Nightmare and Cervantes de Leon

Namco vs Tecmo, weapon-style.

At the Sacred Wilderness training ground, Kasumi and Ayane discover a portal which takes them to feudal Japan. They call a truce so they can work together in order to get back to their time.

Armed with metal gauntlets, a memento from Heihachi's trek through the place prior to their arrival, Kasumi and Ayane run into Cervantes and Nightmare who are currently dueling. Apparently, both sisters must have skipped Ninja Stealth Class (or haven't taken it seriously), since both men turn their sights on the two kunoichi.

The ninja girls get owned. Cervantes is quasi-immortal, and Nightmare is the incarnation of Soul Edge. Not to mention the soul stealing power of their swords.

Nightmare and Cervantes are ultimate badasses, and are therefore harder than children.

I've played Soul Caliber, but I'm not claiming to be an expert on the characters. What exactly do Nightmare and Cervantes have over the sisters? What are their canon feats and abilities?

Cervantes can take summon the undead. And is and undead immortal himself, with a souls stealing sword.

Nightmare, takes down entire armies single handedly, can create gigantic blast, has thousands of years of experience, is an immortal, and has a soul stealing sword.

Nightmare and Cervantes.