Mass Hysteria is a rare Priest spell card that belongs to the "Rastakhans Rumble" set, which was released on 04.12.2018 and is one of initially 135 cards. The artist of this card was Vladimir Kafanov, who also made 99 other artworks for Hearthstone.
The flavor text of the card is the following: Black Friday gets worse every year.
The card is easy to memorize with 96.7% of correct quiz questions.
