In the bottom of the current event "rewards" menu, where the minumun score to acces the % rewards should appear, the text is a nonsense. May be a bad English-Spanish translation. It says the following (translated to english): "Chance of 60,000 of removing every beneficial COMBAT EFFECT of the opponent (when ¡Pick up the event rewards in the mail once the event has finished!" The original text, in spanish, is the following: "Probabilidad del 60,000 de quitar todo EFECTO DE COMBATE beneficioso del oponente (al ¡Recoge recompensas de evento en el correo una vez el evento haya finalizado!" Not sure if this is limited to the current event or it happened before.