The opponent issues an attack. You hear a quiet tune. It's so faint and so distant that you can't help but notice it. But once you acknowledge it, there's no blocking it out. It gets louder and louder, slowly at first but then shooting up into an explosive high-pitched shriek, pausing for no one and nothing.
As suddenly as it came, it pitches up and out of range of the human ear. But your Pokemon aren't human, are they? You notice their pupils dilate just before shrinking to a size you imagined to be impossible, their eyes now wide as can be with unknowable terror. They start to claw at their ears, unable to bear the tone. You call out to them, begging them to stay focused and to not give in to the descending madness, and they do their damnedest because they trust you to be their guiding light back to peace and sanity. But not even that love and loyalty can save them.
With labored huffs they struggle to dole out their next attacks and look to you after each completed action for support. You cheer them on, though you know what is to come. No Pokemon has ever lasted long enough to make more than three attacks after hearing the song.
You select each move carefully yet quickly, having each ring out in the most confident command you can muster. Your voice mustn't waver. For their sake. You choose powerful attacks, risky ones. Their last memories must be proud ones, proud of the strength they've mustered, proud of the conditions in which they did so, proud of their refusal to capitulate to the opponent's trick.
You issue the final command, and your Pokemon respond though their bodies quake with each shallow breath they take. The song is rooted too deeply now. They collapse. They don't have long. You run onto the field regardless of the danger, of the opponent's Pokemon who are still very much alive and who are unlikely to show restraint with victory so near. You pull them both to your chest and cradle their heads, whispering how well they did and how proud you are of them as their eyes dull and they slip from consciousness.
You distantly hear your opponent laugh. It's a shame this wasn't for money, the voice says. There's a small thump in the dust beside you, and an item glimmers mockingly, even in the overcast sky. They would have very much enjoyed the benefits of their amulet coin.