呪術の元凶
Source of The Curse is a Weiß Schwarz card from 「Re:ゼロから始める異世界生活」Vol.2 RZ/S55-050. Compare listings from Singapore Weiß Schwarz sellers on CardJio, then jio them on WhatsApp.
If you have 2 or less 《Magic》 or 《Weapon》 characters, this card cannot be played from your hand. Draw up to 2 cards, choose 2 cards in your hand, put them into your waiting room, choose 1 of your opponent's characters, that character gets -1000 power until end of turn, choose 1 of your characters, and that character gets +1000 power until end of turn.