H.P. Clancy is the main antagonist in Ninja Gaiden III: The Ancient Ship of Doom.
Clancy was hired by Foster who is one of Ryu Hayabusa's enemies. Together, they built a laboratory where they conduct experiments on human beings. They hope to find and acquire more energy. Clancy, however, has other intentions.
Ryu Hayabusa encounters Clancy in the laboratory where he and Foster work. Clancy instructs Ryu to go to a place called the Castle Rock Fortress. However, Clancy does not reveal his identity. Ryu follows the instruction. Along the way, Ryu encounters his old nemesis: Foster. He claims to be waiting at the Castle-Rock Fortress. Further in the journey, Ryu encounters Clancy again.
At this point, Clancy reveals himself. He and Foster worked on making creature's known as Bio-Noids. The source of the creature's power was from an inter-dimensional rift. The Castle-Rock Fortress is at the rift. Clancy also claims to lose interest in working with Foster. Eventually, Ryu arrives at the Castle Rock Fortress. After infiltrating the ruins, Ryu confronts Foster in person. However, Clancy steps in to assume control of the ruins much to the Foster's surprise.
Clancy retreats through the trans-dimensional rift. Foster attempts to follow but he is eviscerated. Ryu follows in Clancy. Within the the lower levels of the trans-dimensional ruins, Ryu confronts Clancy. He reveals the true nature of the ruins: they are an inter-dimensional warship. By using the ship's enormous power, Clancy intends to reshape the world starting with the genocide of humanity.
Clancy, impressed with Ryu's skills and tenacity, made a proposition: join with Clancy in his genocidal quest to create a new world and co-rule it with him. Clancy would even arrange a chosen human of Ryu's liking (no doubt referring to Irene Lew) to be remade and stand by their sides. Ryu of course refuses and they fight. Clancy is killed by Ryu in their final confrontation. The warship is then destroyed.
Clancy is xenophobic in nature. He views other humans as pitiful and destructive. Clancy is also shown to be manipulative. He will befriend anyone who seems useful to him. Afterwards, he will not hesitate to kill them.