These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Genma's minion Tessai deserves a mention as well. Tessai is a bloodthirsty maniac who cheerfully mows down dozens of people and takes the surviving women as his rape victims. While molesting Kagero, he tells her not to struggle because he wouldn't mind having sex with a dead chick.
Crosses the Line Twice - It would take a page unto itself to list that which happens in this film.
Gateway Series: No doubt this has been many peoples' introduction to anime.
High Octane Nightmare Fuel: Highlights include: Tessai's sickening massacre of the Koga ninja; Benisato using the skin of an old woman filled with serpents so she could lure Jubei where she wanted to trap him; the death of Mushizo when he falls underwater and is torn apart from the inside out by the hornets trying to escape his body; and of course, Genma's death scene.
What Do You Mean, It's Not for Kids?: No, this is not like Naruto, despite being Anime with ninjas. Tessai's gory slaughter of the Koga ninja and attempted rape of Kagero should be your first clues.