Rental Magica/YMMV

• High Octane Nightmare Fuel
  • Yeah, just at the first (broadcast) episode an old man who supposed to be dead resurrected... wait, that's not an undead, it's like something from.... oh my! Eldritch Abomination!
  • And don't get us started with Oswald Lenn Mathers in the fifth and sixth episode, who is a formless monster that can use any demonic form he desires...
  • Fin Cruda in the last three (broadcast) episodes, along with The Dragon, is what could be described by this troper "If Giygas has human form"...
  • Then there's the giant, floating larva in Sekiren's debut episode. (shudder) Coincidentally, it actually does have the power to cause nightmares in the show itself.