Hexerei
Opfere eine Kreatur. Wenn du dies tust, erhalten alle Kreaturen bis zum Ende des Zuges -X/-X, wobei X gleich der Widerstandskraft der geopferten Kreatur ist.
You don’t choose which creature to sacrifice until Tip the Scales resolves. You must sacrifice exactly one creature if you control one at that time. Doing so causes a “reflexive” ability to trigger. Players may respond to that ability knowing the value of X.
Use the sacrificed creature’s toughness as it last existed on the battlefield to determine the value of X.