Hydra-Zähmerin

Du kannst die Hydra-Zähmerin erschöpfen, sowie sie angreift. Wenn du dies tust, erhält eine Kreatur deiner Wahl bis zum Ende des Zuges +X/+X, wobei X gleich der Anzahl an Marken auf Permanenten ist, die du kontrollierst. (Eine erschöpfte Kreatur enttappt nicht während deines nächsten Enttappsegments.)
{2}{G}: Adaptieren 2. (Falls keine +1/+1-Marken auf dieser Kreatur liegen, lege zwei +1/+1-Marken auf sie.)

Entrenadora de hidras

Puedes espolear a la Entrenadora de hidras en cuanto ataque. Cuando lo hagas, la criatura objetivo obtiene +X/+X hasta el final del turno, donde X es la cantidad de contadores sobre los permanentes que controlas. (Una criatura espoleada no se enderezará durante tu próximo paso de enderezar.)
{2}{G}: Adaptar 2. (Si esta criatura no tiene contadores +1/+1 sobre ella, pon dos contadores +1/+1 sobre ella.)

Instructrice d'hydres

Vous pouvez surmener l'Instructrice d'hydres au moment où elle attaque. Quand vous faites ainsi, une créature ciblée gagne +X/+X jusqu'à la fin du tour, X étant le nombre de marqueurs sur les permanents que vous contrôlez. (Une créature surmenée ne se dégage pas pendant votre prochaine étape de dégagement.)
{2}{G} : Adaptez 2. (Si cette créature n'a pas de marqueurs +1/+1 sur elle, mettez deux marqueurs +1/+1 sur elle.)

Addestratrice di Idra

Puoi stremare l'Addestratrice di Idra mentre attacca. Quando lo fai, una creatura bersaglio prende +X/+X fino alla fine del turno, dove X è il numero di segnalini sui permanenti che controlli. (Una creatura stremata non STAPpa durante il tuo prossimo STAP.)
{2}{G}: Adattamento 2. (Se questa creatura non ha segnalini +1/+1, metti due segnalini +1/+1 su di essa.)

ハイドラの調教師

ハイドラの調教師が攻撃するに際し、これを督励してもよい。そうしたとき、クリーチャー１体を対象とする。ターン終了時まで、それは＋Ｘ/＋Ｘの修整を受ける。Ｘは、あなたがコントロールしているすべてのパーマネントの上にあるカウンターの総数に等しい。（督励されたクリーチャーは、次のあなたのアンタップ・ステップにアンタップしない。）
{2}{G}：順応２を行う。（このクリーチャーの上に＋１/＋１カウンターがないなら、これの上に＋１/＋１カウンター２個を置く。）

Treinadora de Hidras

Você pode exaurir Treinadora de Hidras conforme ela ataca. Quando você faz isso, a criatura alvo recebe +X/+X até o final do turno, sendo X o número de marcadores nas permanentes que você controla. (Uma criatura exaurida não será desvirada durante sua próxima etapa de desvirar.)
{2}{G}: Adaptar 2. (Se esta criatura não tiver marcadores +1/+1, coloque dois marcadores +1/+1 nela.)

多头龙驯师

你可以于多头龙驯师攻击时耗竭之。当你如此作时，目标生物得+X/+X直到回合结束，X为由你操控的永久物上之指示物总数量。（已耗竭的生物于你的下一个重置步骤中不能重置。）
{2}{G}：演化2。（如果此生物上没有+1/+1指示物，则在其上放置两个+1/+1指示物。）

Hydra Trainer

You may exert this creature as it attacks. When you do, target creature gets +X/+X until end of turn, where X is the number of counters on permanents you control. (An exerted creature won't untap during your next untap step.)
{2}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)

Modern Horizons 3

You may exert Hydra Trainer as it attacks. When you do, target creature gets +X/+X until end of turn, where X is the number of counters on permanents you control. (An exerted creature won't untap during your next untap step.)
{2}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)

If a creature somehow loses all of its +1/+1 counters, it can adapt again and get more +1/+1 counters.

If an exerted permanent is already untapped during your next untap step (most likely because an effect untapped it), exert's effect preventing it from untapping expires without having done anything.

If you gain control of another player's permanent until end of turn and exert it, and then that player regains control of it, it will untap during that player's untap step.

The value of X is determined only once, as the reflexive triggered ability resolves.

You can always activate an ability that will cause a creature to adapt. As that ability resolves, if the creature has a +1/+1 counter on it for any reason, you simply won't put any +1/+1 counters on it.

You can exert Hydra Trainer as you declare it as an attacking creature. You can't do so later in combat, and creatures put onto the battlefield attacking can't be exerted. Any abilities that trigger on exerting an attacking creature will resolve before blockers are declared.

You don't choose a target for Hydra Trainer's first ability at the time it triggers. Rather, a second "reflexive" ability triggers when you exert Hydra Trainer this way. You choose a target for that ability as it goes on the stack. Each player may respond to this triggered ability as normal.