Genji/YMMV

• 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....

Undead Moritoshi: "YOOOOOOOOOOOSHIIITSUUUUUUNEEEEEEEEEEEE........ KIIIIIIILLLLL...."

• 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.
• Memetic Mutation - Due to one type of crab. In fact, the pages the game is trope namer to were created much earlier than the page for Genji itself.