In "The House of Hades" by Rick Riordan, the character Leo recognizes the risks associated with making oaths, particularly those sworn on powerful symbols. Despite this awareness, he feels a strong determination and emotional connection driving him to take the risk. His resolve highlights the intensity of his feelings for Calypso.

Leo's vow underlines a central theme of loyalty and commitment, emphasizing how love can compel individuals to take grave risks. His promise, made amidst the uncertainties of his journey, reflects both his courage and the personal stakes involved, illustrating the depth of his bond with Calypso.