*offers a fine wine, sends in a few mon-keigh slaves over, and hands some of the wych-cults finest* Drink and enjoy, use the humans for whatever you want, and take only small doses of this! You brought your own weapons, I hope, and you hopefully know how to avoid poison. You can find antidote for any poison in... nowhere. Enjoy your stay, and welcome to Commorragh, the city of eternal smiles, both carved ones and the ones on the lips! We also offer very delicate "The Joker"-smiles to keep your face eternally smiling, for reasonable prices! Feel No Pain required for survival.
It sometimes feels like I am the ONLY Night Lord who can smile... Sometimes I even have a little chuckle... In fact I have been known to indulge myself with some full-blown maniacal laughter!
*drinks the wine, burps, farts...smiles. 'Ahh delicious, don't you have some more my dear? Oh, one more thing, I think there's no need for your Joker Smiles offer - just look at me my dear *
Other 40K factions lack humour, doesn't make them Chaosy. But yeah, they are a bit too serious for my tastes. =)