There may be epic poems that detail his entire story. These would likely cover his early days in the Tokugawa family, his training and education, his rise to the position of shogun, and then the events that led to his downfall. Such a poem would be a rich tapestry of historical events and personal experiences, like a long saga.
One poem might be about his rise to power. It could describe how he ascended to a position of great influence within the Tokugawa shogunate. Maybe it would mention his leadership during a time of political unrest.