Professorin Onyx

Magiefertigkeit — Immer wenn du einen Spontanzauber oder eine Hexerei wirkst oder kopierst, verliert jeder Gegner 2 Lebenspunkte und du erhältst 2 Lebenspunkte dazu.
+1: Du verlierst 1 Lebenspunkt. Schaue dir die obersten drei Karten deiner Bibliothek an. Nimm eine davon auf deine Hand und lege den Rest auf deinen Friedhof.
−3: Jeder Gegner opfert eine Kreatur mit der höchsten Stärke unter den Kreaturen, die er kontrolliert.
−8: Jeder Gegner kann eine Karte abwerfen. Falls er dies nicht tut, verliert er 3 Lebenspunkte. Wiederhole diesen Vorgang noch sechs Mal.

Profesora Ónix

Hechicería — Siempre que lances o copies un hechizo de instantáneo o de conjuro, cada oponente pierde 2 vidas y tú ganas 2 vidas.
+1: Pierdes 1 vida. Mira las tres primeras cartas de tu biblioteca. Pon una de ellas en tu mano y el resto en tu cementerio.
−3: Cada oponente sacrifica una criatura con la mayor fuerza entre las criaturas que controla ese jugador.
−8: Cada oponente puede descartar una carta. Si no lo hace, pierde 3 vidas. Repite este proceso seis veces más.

Professeur Onyx

Sorcellerie — À chaque fois que vous lancez ou copiez un sort d'éphémère ou de rituel, chaque adversaire perd 2 points de vie et vous gagnez 2 points de vie.
+1: Vous perdez 1 point de vie. Regardez les trois cartes du dessus de votre bibliothèque. Mettez l'une d'elles dans votre main et le reste dans votre cimetière.
-3: Chaque adversaire sacrifie une créature avec la force la plus élevée parmi les créatures que ce joueur contrôle.
-8: Chaque adversaire peut se défausser d'une carte. S'il ne le fait pas, il perd 3 points de vie. Répétez ce processus six fois.

Professoressa Onyx

Artemagica — Ogniqualvolta lanci o copi una magia istantaneo o stregoneria, ogni avversario perde 2 punti vita e tu guadagni 2 punti vita.
+1: Perdi 1 punto vita. Guarda le prime tre carte del tuo grimorio. Aggiungine una alla tua mano e metti le altre nel tuo cimitero.
−3: Ogni avversario sacrifica una creatura con la forza maggiore tra le creature che controlla.
−8: Ogni avversario può scartare una carta. Se non lo fa, perde 3 punti vita. Ripeti questo procedimento altre sei volte.

オニキス教授

魔技 ― あなたがインスタントやソーサリーである呪文１つを唱えるかコピーするたび、各対戦相手はそれぞれ２点のライフを失い、あなたは２点のライフを得る。
+1：あなたは１点のライフを失う。あなたのライブラリーの一番上にあるカード３枚を見る。そのうち１枚をあなたの手札に、残りをあなたの墓地に置く。
-3：各対戦相手はそれぞれ、自分がコントロールしているクリーチャーの中で最大のパワーを持つクリーチャー１体を生け贄に捧げる。
-8：各対戦相手はそれぞれカード１枚を捨ててもよい。そうしなかったなら、そのプレイヤーは３点のライフを失う。この手順をもう６回繰り返す。

Professor Onyx

Magecraft — Whenever you cast or copy an instant or sorcery spell, each opponent loses 2 life and you gain 2 life.
[+1]: You lose 1 life. Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
[−3]: Each opponent sacrifices a creature with the greatest power among creatures that player controls.
[−8]: Each opponent may discard a card. If they don't, they lose 3 life. Repeat this process six more times.

Duskmourn: House of Horror Commander

Magecraft — Whenever you cast or copy an instant or sorcery spell, each opponent loses 2 life and you gain 2 life.
+1: You lose 1 life. Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
−3: Each opponent sacrifices a creature with the greatest power among creatures that player controls.
−8: Each opponent may discard a card. If they don't, they lose 3 life. Repeat this process six more times.

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 Each magecraft ability has a different effect, although they all have the same trigger condition, whenever you cast or copy an instant or sorcery spell.

 For example, if you control Archmage Emeritus and cast an instant or sorcery spell, Archmage Emeritus's magecraft ability will trigger and you will draw a card.

 If an effect creates a copy of an instant or sorcery spell, this will also cause the magecraft ability to trigger.

 If an effect creates multiple copies of an instant or sorcery spell, magecraft abilities trigger once for each copy created by the effect.

 Some effects instruct you to copy an instant or sorcery card in a zone other than the stack. These copies do not cause magecraft abilities to trigger. However, most effects that do this also allow you to cast the copy, and casting the copy will cause magecraft abilities to trigger.

For Professor Onyx's last loyalty ability, "this process" is the following: First, the next opponent in turn order may choose a card in hand without revealing it, then each other opponent in turn order does the same. Then all the chosen cards are revealed and discarded at the same time and each opponent who didn't discard a card (whether they chose not to or had an empty hand) loses 3 life. This all will happen seven times, for a maximum loss of 21 life per opponent.

For Professor Onyx's second loyalty ability, if an opponent has multiple creatures with the greatest power, that player choose which one to sacrifice. The next opponent in turn order chooses which creature they are sacrificing, then each other opponent in turn order does the same, knowing the choices made before them. Then all chosen creatures are sacrificed at the same time.

If Professor Onyx seems familiar, it's probably because you've seen this type of planeswalker before.