William is an English sailor. Orphaned at an early age, he survived by hunting for Spirit Stones, assisted by his Guardian Spirit Saoirse who possesses the power to detect Amrita
Then one day, Saoirse was seized by an alchemist by the name of Edward Kelley.
William pursued Kelley across the oceans, eventually finding himself in Japan.
After encountering Hattori Hanzo and Tokugawa Ieyasu, he managed to defeat Edward Kelley and was reunited with Saoirse.
He then returned to England to defeat the evil figure behind all that had unfolded.
Returning to Japan, William heads to Oshu to come to the aid of Hattori Hanzo.
He encounters a woman named Maria who has allied with Date Masamune in order to spark a new wave of civil war and use the ensuing chaos to obtain Spirit Stones.
Hearing that Maria is in Byodo-In, William hurries to the temple. It is here that he encounters the protagonist whose eyes are glowing red and engages in combat.