1st inter-portal tournament of HMM3-OFF: "Air Magic"

I request to be registered for the tournament. However, the check for the possibility of morale/luck/... dropping in battles is still unclear to me. Therefore, I ask you to answer a specific question: "Can we expect that a stack of Grand Genies will cast a specific spell on the first turn. Assume that if this spell is cast, the battle will be won with a probability of at least 66%." According to my calculations, the probability that the battle will be won at least once in 25 attempts under the specified conditions is more than 79%.