vibe assassin 

one who, through social awkwardness or overall douchiness, is able to eradicate the good-time party feeling from a room instantly.

Don't invite that guy. Last time he totally killed my buzz -- he's a vibe assassin.

vibe assassin by Rachel_from_Vegas June 16, 2008

Vibe assassin 

People that kill your vibe for no reason. Buzz killers. Kill joys. Hating ass muhfuckas.

Don’t invite Keith to the party he’s a fuckin vibe assassin. Always on bullshit.

Vibe assassin by iamanthonydean June 9, 2023