Lightsaber 3.0 mod overrides this mod because they use the same vendor for items. 
To gain access to the ninja gear, remove Lightsaber 3.0 from your resources folder.

The vendor is located in the Potion Shop in Eldim. There are 3 summon spells which 
appear with red icons, so you can't miss them. The spells are found randomly at any 
town spell vendor. 

One thing I have found is that Ninja mod and Lightsaber 3.0 mod can run together, 
and random monster drops can on occaison drop a piece of magical ninja/samurai gear, 
and is compatible with other mods like Set Items mod and Chicken World mod. The only 
thing is that the Lightsaber 3.0 mod overrides the vendor in Eldim, so nonmagical 
ninja/samurai gear is not available.

Unfortunately there are no English names on the items themselves, but the spell 
descriptions are in English. On a good note, this does make the ninja/samurai gear 
easily seen among a pile of gold and armor and weapons.