Sure, they seem super cool.
They will sit in the corner smoking a cigarette and drinking whiskey.
Their presence will lend an air of legitimacy to the party.
They will scowl and act bored.
(They are not really bored.)
They are sitting there soaking it up.
Watching the way everyone moves 
And listening to the conversations around them
Feel the uncomfortable spaces inbetween 
The awkwardness of forced interactions
And the hiss of the bottle opening
And the click of amber glass.
They may not say a word beyond “hey”
They will sit in their corner stewing over their drink.
Sure they will look cool.
But truly they are not.
They are the worst party guess.
Eventually they might speak and it will bring down the mood.
They will mention despair and crows and the trees grow.
They will say they say the reflection in a diamond ring.
They will start talking about the economy and how they are never payed.
They might if you are lucky retell a story about Aphrodite and Ares.
You will have no idea what they are talking about
But a hush will fall on the party as voices fade to one.