[FR] What Demon should I throw at my PCs?

[Romnipotent]

Imp Sorcerer level 10 with leadership and a devoted defender Imp brother... that will throw them off centre
And after all, its just a blinking imp

 

[Shemeska]

Quasits with rogue levels. Quasits are so annoyingly pissy if they start having 'fun' with tormenting your PCs, they'll be loathed.

At roughly the level of your PCs I also tossed a Vrock w/ fighter levels and a warptouch sword, two shadow fiends, and a metric ton of manes at my PCs. It would have gone better but one of them used a Holy Word (when one two PCs were actually good aligned).

And you could always have Vhok hire some Yugoloth mercenaries to send after your PCs.

 

[Lazybones]

I have a particular fondness for ghour demons (CR12) from Monsters of Faerun.

 

[Pants]

I'm a self pimp...

Check out my website. I've done a bunch of fiendish conversions that you might find handy, including the Chasme (CR 11) and Greater Babau (CR 13).