Though the Ninja family has not appeared in any Seiken Densetsu game since SD3, they were previously employed in the games as very powerful enemies. Ninjas are fast and strong attackers, usually using a mix of swords and throwing stars. The Seiken Densetsu Ninjas differ from most in that they wear quite a bit of armor, and rely on strength more than stealth. The Ninjas appear to be ready for combat in sandy areas with their caps resembling havelock caps. The Ninjas have the ability to melt into their shadows and move around at high speeds.
The Ninjas in FFA are one of the enemies encountered at the very end of the game inside the Mana Tower. They are not paired with any other enemies. The Ninjas jump around the screen randomly and occasionally shoot throwing stars. The Samurai Helmet, the strongest helmet in the game, is only dropped by the Ninjas.
In SoM Ninjas are classified as Dragons.
The red and green clad Dark Ninjas live inside the Palace of Darkness, the Emperor’s Castle and in the Gold Tower. They carry a magic scroll which they can lift from the ground and make themselves invisible. Usually when they are invisible they will pop their heads over the scroll and give themselves away. They can seemingly turn invisible at will while moving around, only allowing their shadow to be seen. They attack with Shurikens and Swords. Dark Ninjas tend to cast Flame Sabre on themselves, and will sometimes use Burst as a suicide tactic.
The character Sheex once used a Dark Stalker as a disguise after the heroes discovered he was spying on Tasnica by pretending to be the king. Dark Stalkers can be summoned by Fiend Faces in the Mana Fortress and have been known to drop a Glove Orb. They share a name with a Knight from FFA and LoM, but there is no connection between them. Darkstalkers act the same as the Ninja before them but will cast Ice Sabre and seem to enjoy casting Dispel. They drop Gauntlets.
Master Ninja / Ninja Master (J)
Master Ninjas are one of the strongest enemies in Secret of Mana. These golden ninja warriors are found on the last level of the Mana Fortress. They are very similar to the other Ninjas, but they will cast Stone Sabre on themselves and are much more agressive. There is a chance they will drop a Boomerang Orb or a Faerie Ring.
In SD3 Ninjas are classified as Dragons.
These enemies found in the Navarre Sand Fortress are decked out in green, brown and white gear typical of Seiken Densetsu Ninjas. Their abilities correspond to Hawk’s Ninja class. They can use all different elemental Jutsus, throw Shurikens and use the Silhouette Slice ability.
Ninja Masters hang out in Navarre and in the Valley of Flames. These purple and orange Ninjas use a variety of upper level Jutsus and Shurikens to fight. They are strong to almost all elements, but have a low HP for their level. They follow Hawk’s Ninja Master class, and so gain the Shadow Dive technique.
Found in the Glass Desert, these dark grey, blue and brown warriors are some of the quickest enemies in SD3. They follow Hawk’s Night Blade class, and gain many devastating spells. They can breathe fire, blow needles, throw a wrench at you and use the Split Image Splice technique.
Bill and Ben
Bill and Ben were two of Hawk’s friends before problems started to arise in Navarre. The two can combine into a single person, and once taking enough damage will split into two to fight. They are able to use Shurikens, Jutsus and many Ninja techniques. These characters are apparently not Monsters, so it is unclear if all Ninjas are humans or otherwise.