Heres my reccomendations for anyone that likes Action, Ninja anime, especially more serious, for adults. not that high schoool girly shit anime i don't know how people like that stuff especially dudes
-Ninja Scroll(movie and series)
-DesertPunk(not ninja but very likable if you give it a chance)
I've been on a Netflix anime kick and finishing up Morbito now, and loving it. Only one i sort of didn't like that i listed was the ending of Basilisk and DesertPunk not having more to it. Otherwise these are all heavy action, some very adult oriented hardcore, and most importantly not gay as shit like 3/4's of the anime people recommend to me. Honestly somje of the anime's i've been recommended are so homo i've lost trust in anime advice more than randomly trying stuff based on the covers and previews.