The Samurai warriors are mechanical giants that hold deadly weapons inculding swords and even a giant minigun. They are highly trained warriors.
In the Splastk short film Feudal Warriors, made for the promotion of Sucker Punch, explains that the creatures are products of Lord Kougun, Master of the Black Arts, who used a forbidden enchantment to make an army of demon samurai. They conquered sacred sanctuaries all over the world and throughout time so Kougun could steal their mystical power and become stronger.
When they seek to drain the Temple of Mount Mukasa (the dojo in the first fantasy reality), they must fight Babydoll. Lord Kougun does not take part in the fight. The three samurai battle her one-by-one and they all lose.