I would think that the most important aspect of one's character to determine moral virtue or moral excellence is some understanding of right vs. wrong, determined by religious or cultural background, or a philosophy, that provides guidelines with which a person learns how to "behave" within the norms of his or her society. One aspect of this posting makes note of "isolation." My perception is that in isolation, I don't know how a person would learn to be "morally sound." Without guidelines of a social or religious nature, one would learn to survive, and do whatever was necessary to do so. Isolation would have to be complete, for while animals are not "moral" creatures, they have rules that the pack or species follows. For example, with wolves, the cubs are taken care of, but they wait their turn to eat—or are lightly "punished." Geese and cardinals mate for life, but this is particular to their nature, for other birds, fowl, etc., are not this way.
With this in mind, moral virtue encompasses respect, compassion, forgiveness and selflessness. It is a conscious decision that remains steadfast in spite of how others act. However, in this instance, can a question be asked in isolation to a specific circumstance with a morally virtuous person? I believe it can be here, for a moral individual will be consistent in exercising ethical behavior...always with the elements of respect, compassion, etc., in mind.