Bann alles Lebens

Morph {X}{B}{B} (Du kannst diese Karte verdeckt für {3} als eine 2/2 Kreatur wirken. Decke sie zu einem beliebigen Zeitpunkt für ihre Morph-Kosten auf.)
Wenn der Bann alles Lebens aufgedeckt wird, erhalten alle Kreaturen -X/-X bis zum Ende des Zuges.

Ruina de los vivos

Metamorfosis {X}{B}{B}. (Puedes lanzar esta carta boca abajo como una criatura 2/2 pagando {3}. Ponla boca arriba en cualquier momento pagando su coste de metamorfosis.)
Cuando Ruina de los vivos se pone boca arriba, todas las criaturas obtienen -X/-X hasta el final del turno.

Fléau des vivants

Mue {X}{B}{B} (Vous pouvez lancer cette carte face cachée comme une créature 2/2 pour {3}. Retournez-la à tout moment pour son coût de mue.)
Quand le Fléau des vivants est retourné face visible, toutes les créatures gagnent -X/-X jusqu'à la fin du tour.

Sventura dei Viventi

Metamorfosi {X}{B}{B} (Puoi lanciare questa carta a faccia in giù come una creatura 2/2 pagando {3}. Girala a faccia in su in qualsiasi momento pagando il suo costo di metamorfosi.)
Quando la Sventura dei Viventi viene girata a faccia in su, tutte le creature prendono -X/-X fino alla fine del turno.

生命を破滅させるもの

変異{X}{B}{B}（あなたはこのカードを、{3}で２/２クリーチャーとして裏向きに唱えてもよい。これの変異コストで、これをいつでも表向きにしてよい。）
生命を破滅させるものが表向きになったとき、ターン終了時まで、すべてのクリーチャーは－Ｘ/－Ｘの修整を受ける。

Perdição dos Vivos

Metamorfose {X}{B}{B} (Você pode conjurar este card com a face voltada para baixo como uma criatura 2/2 por {3}. Volte sua face para cima a qualquer momento pagando seu custo de metamorfose.)
Quando Perdição dos Vivos tem a face voltada para cima, todas as criaturas recebem -X/-X até o final do turno.

夺命邪祟

变身{X}{B}{B}（你可牌面朝下地施放此牌并支付{3}，将其当成2/2生物。可随时支付其变身费用使其翻回正面。）
当夺命邪祟翻回正面时，所有生物得-X/-X直到回合结束。

Bane of the Living

Morph {X}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, all creatures get -X/-X until end of turn.

Commander 2019

Morph {X}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Bane of the Living is turned face up, all creatures get -X/-X until end of turn.

Commander Anthology Volume II

Commander 2016

Legions

Morph {X}{B}{B} (You may play this face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Bane of the Living is turned face up, all creatures get -X/-X until end of turn.

The X in the ability has the same value as the X paid in the Morph ability. This is pretty easy to derive since there is no other source of X.

The trigger occurs when you use the Morph ability to turn the card face up, or when an effect turns it face up. It will not trigger on being revealed or on leaving the battlefield.