The Rakdos use it for everything you can think of and plenty more than that.

Die Rakdos benutzen ihn für alles, was man sich nur vorstellen kann, und noch für vieles mehr.

Rakdos-Runenschlüssel

{T}: Erzeuge {B} oder {R}.
{B}{R}: Der Rakdos-Runenschlüssel wird bis zum Ende des Zuges zu einer 3/1 schwarzen und roten Teufel-Artefaktkreatur mit Erstschlag.

Los rakdos la utilizan para todo cuanto se te ocurra y para muchas cosas más.

Llave rúnica rakdos

{T}: Agrega {B} o {R}.
{B}{R}: La Llave rúnica rakdos se convierte en una criatura artefacto Diablo negra y roja 3/1 con la habilidad de dañar primero hasta el final del turno.

Les Rakdos s'en servent pour tout ce qui vous vient à l'esprit, et bien plus encore.

Runeclé de Rakdos

{T} : Ajoutez {B} ou {R}.
{B}{R} : La Runeclé de Rakdos devient une créature-artefact 3/1 noire et rouge Diable avec l'initiative jusqu'à la fin du tour.

I Rakdos la usano per tutto quello che puoi immaginare... e molto altro ancora.

Runachiave Rakdos

{T}: Aggiungi {B} o {R}.
{B}{R}: La Runachiave Rakdos diventa una creatura artefatto Diavolo 3/1 nera e rossa con attacco improvviso fino alla fine del turno.

ラクドス教徒はこれをあなたが考え得るあらゆることに、そしてその想像を超えたことに使用する。

ラクドスの魔鍵

{T}：{B}か{R}を加える。
{B}{R}：ターン終了時まで、ラクドスの魔鍵は、先制攻撃を持ち黒であり赤である３/１のデビル・アーティファクト・クリーチャーになる。

Rakdos Keyrune

{T}: Add {B} or {R}.
{B}{R}: This artifact becomes a 3/1 black and red Devil artifact creature with first strike until end of turn.

RNA Guild Kit

{T}: Add {B} or {R}.
{B}{R}: Rakdos Keyrune becomes a 3/1 black and red Devil artifact creature with first strike until end of turn.

Return to Ravnica

{T}: Add {B} or {R} to your mana pool.
{B}{R}: Rakdos Keyrune becomes a 3/1 black and red Devil artifact creature with first strike until end of turn.

Activating the ability that turns the Keyrune into a creature while it's already a creature will override any effects that set its power and/or toughness to another number, but effects that modify power and/or toughness without directly setting them will still apply.

Until the ability that turns the Keyrune into a creature resolves, the Keyrune is colorless.