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.
Demonic Spiders: The monsters you fight in the later levels, including those dragon-like humanoids and the green sumo-ogres.
Goddamn Bats: those small scarabs in the Golden Temple. You'll require a double Kamui if you hope to hit them.
Nightmare Fuel: The giant monster summoned by Kuyo, which is made of screaming human skeletons nailed together!. also Undead Moritoshi, as soon as you realize that now his very face is a mask.. not mentioning his voice....