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 conducted experiments on human beings. They hoped to find and acquire more energy. Clancy, however, had other intentions.
Ryu Hayabusa encountered Clancy in the laboratory where he and Foster worked. Clancy instructed Ryu to go to a place called the Castle Rock Fortress. Clancy did not reveal his identity. Ryu followed the instruction. Along the way, Ryu encountered his old nemesis: Foster. He claimed to be waiting at the Castle-Rock Fortress. Further in the journey, Ryu encountered Clancy again.
At this point, Clancy revealed himself. He and Foster worked on making creatures known as Bio-Noids. The source of the creatures' power were from an inter-dimensional rift. The Castle-Rock Fortress was at the rift. Clancy also claimed to have lost interest in working with Foster. Eventually, Ryu arrived at the Castle Rock Fortress. After infiltrating the ruins, Ryu confronted Foster in person. Clancy stepped in to assume control of the ruins much to the Foster's surprise.
Clancy retreated through the trans-dimensional rift. Foster attempted to follow but he was eviscerated. Ryu followed in Clancy. Within the lower levels of the trans-dimensional ruins, Ryu confronted Clancy. He revealed the true nature of the ruins: they were an inter-dimensional warship. By using the ship's enormous power, Clancy intended to reshape the world starting with the genocide of humanity.
Clancy, impressed with Ryu's skills and tenacity, made a proposition for the ninja: 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 refused the offer and they fought. Clancy was killed by Ryu in their final confrontation. The warship was then destroyed. Afterwards, Ryu reunited with Irene and they watched the sun rise over the horizon.
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.