Before the Black Death destroyed the vast majority of those Priests who put the cares of their congregation before the cares of themselves, Christianity during this period was going through a flowering of growth. Aristotelian logic was replacing Platonic absolutism through the work of Thomas Aquinas. Albertus Magnus laid the foundations of scientific thought and exploration in a church embracing the exploration and understanding of the world and its workings. The Fourth Laterine Council recognized both Eucharist and Penance as Holy Sacraments. Christianity was even changing its approach to animals through the naturalism of the Franciscans. Christian mysticism flourished, with the music of Hildegard of Bingham and the meditations of Bonaventure being chief examples. Christianity would face its main challenge in this era from the idea of Romantic Love. The idea of devotion to another person instead to God as an act worthy of poetry, story and song spread like wildfire across secular Europe. Christianity would later adopt this idea as core to its teachings, and teach that no marriage was valid unless husband and wife loved each other.
Unicorns are one of the many creatures found in Christian bestiaries, but what made unicorns special was that they couldn’t abide the presence of anyone who was not chaste. Chastity to a medieval person was a very important virtue, but it did not mean virginal (a modern misunderstanding) but rather some one who was virginal until marriage, and then faithful to their spouse.
Nimuë was the student of Merlin who caused him to fall in love with her and then imprisoned him in either a cave or a tree.
The leviathan is a biblical sea monster whom the medieval sailors would blame for many a misfortune at sea.