|H. P. Clancy|
|Debut:||Ninja Gaiden III: The Ancient Ship of Doom|
vDebuting in: Ninja Gaiden III: The Ancient Ship of Doom
Foster's accomplice in The Ancient Ship of Doom, H.P. Clancy helped trigger many of the events during the game, even serving as the hidden main antagonist. Clancy built the Castle Rock Fortress over the ruins of Jaquio's fallen temple, as he and Foster found a continuous supply of life energy within the ruins; Jaquio's downfall left traces of evil surrounding the site, thus the fortress was built to harvest the energy as a power source, and used it on humans for experiments. He seems remorseful for this, however, as he eventually recruits Ryu to take down Foster. This turns out to be part of his plan all along—he ends up betraying Foster by taking full control of the dimensional warship within the castle ruins, merging with the ancient craft. His ultimate goal turns out to be the destruction of humanity, which he hates for .