Unlock: To unlock, complete the mission "????".
William is an Irish-born English sailor. While still a boy, he lost both parents in the Irish war with England, but also met his Guardian Spirit Saoirse; the two have been inseparable ever since. Overcoming these early tragedies, William grew to be a strong and capable young man and threw in his lot with an English navy privateer-a pirate ship in all but name. Saoirse's special ability to locate powerful Amrita spirit-stones allowed him to flourish as a pirate for a time, but when he stumbled upon a secret military project to weaponize Amrita, he was imprisoned in the Tower of London.
Unlock: To unlock, complete the mission "????".Just before William escaped the Tower of London, the alchemist Edward Kelley stole Saoirse from him. Determined to get Saoirse back, William followed Kelley doggedly across perilous seas all the way to Japan. But nothing he had heard about this fabled "country of gold" had prepared him for the realm of supernatural peril and death it proved to be.
Unlock: To unlock, complete the mission "????".On Kelley's trail with Hattori Hanzo, William was favored with an audience with Hanzo's lord, Tokugawa Ieyasu. Although Ieyasu's deep karmic debt forced him to sacrifice much that was dear to him, he remained grimly determined to build a world without war. A question from Ieyasu led William to begin rethinking the meaning of his own power.
Unlock: To unlock, complete the mission "????".William foiled Kelley's plot and won Saoirse back, achieving what he had come to Japan to do. But only then did William learn of the true power behind the events into which he had become swept up. This monstrous foe used the power of Amrita to plague the country with war, sacrificing innocents to the flames of battle. William saw that only by slaying this secret power could the dream of a world without war—a world of harmony between man and spirit—be realised. A new glint of determination appeared in William's eyes, which were now those of a true samurai.
Unlock: To unlock, complete the mission "????".John Dee, the secret power behind events, had been defeated. Surely no one would wish to wage war now. So William believed—before he saw a clear vision of the chaos of battle about to descend on Japan once more. The faces of those he fought alongside in Japan flashed through his mind. Finally, he boarded a ship and set sail for the east once more...
Unlock: To unlock, complete the mission "????".William returned to Japan following a long journey at sea. After reuniting with Hanzo, he stopped the rebellion led by the Tohoku regional warlord, Date Masamune, who was secretly backed by an undercover spy from Spain. Once again, Japan found itself thrown into chaos by forces hoping to use the power of Amrita for military gain.
Unlock: To unlock, complete the mission "????".William headed towards Osaka Castle along with the Date army to face Sanada Yukimura. After fighting his way through the bizarre battlefield all the way to the Sanada Maru and defeating Yukimura, he was unable to stop Maria, the battle's mastermind, from once again making her escape. As a hora—gai shell rang out to signal an end to the battle, William vowed to put a stop to Maria, once and for all.
Unlock: To unlock, complete the mission "????".Six months after the Siege of Osaka's winter campaign, William set off in pursuit of Maria, finding himself once again joining leyasu and his troops besieging Osaka Castle. Together with Date Masamune, he engaged Sanada Yukimura once more in battle in an attempt to prevent the enemy advance, but such efforts proved to be of no avail, as the chaos brought forth by the spirit stones had already taken hold. William hurried to the main keep of the castle with Yukimura and, after a long and perilous fight, defeated Yodogimi, who had taken the form of a giant nine—tailed fox. Upon her defeat, Japan had finally been purged of the forces that sought to use Amrita for their evil machinations, and a world without war envisioned by the Tokugawa clan was finally realised. With Osaka Castle engulfed in flames behind them, William and Hattori Hanzo made their way to Hirado Island in western Hizen province (present—day Nagasaki prefecture).
- Like many other characters in Nioh, William was inspired by a historical figure, William Adams, who was a navigator aboard Dutch East India Company, however, unlike most other characters he's portrayed as a whole different person than his real life counterpart, save for the name and some minor similarities to his journey.
- William is represented wearing the Youngblood Armour in almost every promotial art of the game.