Saika Magoichi is a character newly featured in Sengoku BASARA 3. She is the leader of the proud Saika renegades, a mercenary force that focuses on firearms. Magoichi is a proud woman, who believes wholeheartedly in the strength of the Saika forces.
In Sengoku BASARA 3, Magoichi's path can take two directions; she can either join the Eastern Army and work for Tokugawa Ieyasu or she can join the Western Army under Ishida Mitsunari. Should she work for Ieyasu, she will join the Uesugi forces and catch the eye of Maeda Keijiand Uesugi Kenshin. Swearing his love for her, Keiji will follow her throughout the remaining stages with the Eastern Army; she views him as little more than an annoyance. At the conclusion of Sekigahara, with Ieyasu winning over Mitsunari, she declares their contract over and leaves. If Magoichi joins the Western Army, she swears to continue working for the Ishida forces, impressed by Mitsunari's will. In all other paths, she shows up as an enemy or ally working with the Eastern Army.
It's implied that her name used to be Sayaka; Chosokabe Motochika refers to her as such, despite her insistence that she no longer uses that name. Fighting Oda Nobunaga will reveal that the Demon King killed the former Magoichi, who was her mentor, and that she took up the Magoichi name to lead the Saika force in his stead.
In Sengoku BASARA 4, she can potentially ally with Motochika or Tsuruhime.
And she is reprised by Karen Strassman in the English dub and Sayaka Ohara in the Japanese dub.