Who needs "Monster Bad Guys"?

[Shemeska]

I couldn't have said it better myself.

Muahahahaha!

I've had some spectacular moments with Yugoloths and Rakshasas, and most recently I managed to creep out my players with something that might vaguely be called a risen Tanar'ri.

However the best moment I've had involved a sociopathic human, confined spaces, howling wind, and pitch darkness in the depths of Pandemonium. While fiends were involved in a tangential way, it was all being done by a regular human.