Combine elements of Leonardo da Vinci's "Vitruvian Man," a medieval jousting tournament, a dragon flying overhead, and the Greek god Poseidon emerging from the sea in a fantastical and mythical setting.

Sketch an image that incorporates features from a famous human anatomical diagram of a man with arms and legs stretched out, seen both frontally and from the side, as depicted by pre-1912 artist Leonardo da Vinci, combined with a hallmark event of the middle ages - a jousting tournament. Filling the sky, visualize a massive dragon soaring overhead with its majestic wings spreading wide. From the tumultuous sea in the background, imagine the event of the ancient Greek god of the sea, Poseidon, powerfully emerging, with his iconic trident in hand. This scene melds historical and fantastical elements into a mystical setting.