If only a Succubus could take one, and lay out "You can't touch this" pimp slaps...
Unfortunately as it stands it doesn't even affect sergeants, as its entry specifies only Independent Characters or Monstrous Creatures.
Perhaps if you knew you were going to face an Ork Warboss, or HQs armed with powerfists or axes?Edit:
Come to think of it, if you were deadset on taking one:
Haemonculus Ancient (120pts)
Mindphase guantlet, Power Maul, Vexanthrope
The power maul gives him a chance to bash a higher initiative opponent down to I1, and then next round he slaps him stupid with the mindphase. The Vexanthrope gives him an extra chance to lose his attacks, particularly in a challenge.
I don't think its a good use of points, but it might be fun with a torment launcher nearby.
So if you happened to come across a S4 (base) Ld 9 (because of torment launchers) IC with an Unwieldy weapon like a power fist or thunder hammer, say Lysander, the Ancient above would have 69.5% chance of preventing him from attacking, or 76.3% if he charges. That figure includes the possibility of the Vexanthrope going off, though its contribution is relatively minor.
On the other hand, if Lysander gets to swing he has a 91.2% chance to squit the annoying haemonculus and move on with his life. So while it might be funny for a couple of turns (especially if he has some kind of terminator bodyguard standing and watching while he is trapped in a challenge), prepare to be paste before your flimsy S3 attacks scratch his paint.