Negaviber

A person who spreads negative vibes.
A full-of-negativity motherfucker.

Negative + Viber.

Person 1: You should stop hanging out with Justin.
Person 2: Why's that?
Person 1: Motherfucker's a negaviber, man, he'll kill you with his negativity.

Negavibe

To be negative and have negative vibe

John Doe: DC released a new movie, you going to see it?
Jane Doe: I didn't like the last DC movie, i never like any of them. Life is hell.
John Doe: Damn, girl...you got Negavibe