Amba, who later became, Shikhandi in the Mahabharata had performed intense penance and pleased Kartikeya (Kartik or Murugan) son of Shiva. Kartikeya blessed Amba with a garland. The tale revolves around Amba, daughter of the King of Kashi, longing to wed Shalva, the ruler of Saubha. However, her destiny took a different turn during her swayamvara, where Bheeshma, leader of the Kurus, intervened, claiming her and her sisters as brides for his brother, Vichitravirya. Despite objections and subsequent battles, Bheeshma succeeded, escorting the princesses to Hastinapura. While her sisters accepted their fate, Amba persisted in her desire for Shalva. Bheeshma, respecting her wishes, allowed her to leave, but Shalva rejected her, leaving her in despair.
Returning to Hastinapura, Amba faced rejection from
Vichitravirya due to her prior affections. Left with no alternatives, she
sought marriage with Bheeshma, who declined, bound by his vow of celibacy.
Fueled by anger and humiliation, Amba vowed revenge on Bhishma, seeking
assistance from Lord Kartikeya, who granted her a garland, foretelling its
wearer as the instrument of Bheeshma's downfall. Despite her efforts, no
warrior dared wear it, fearing Bheeshma.
Resorting to penance to invoke Lord Shiva, Amba gained a
prophecy of her future role in Bheeshma's demise. Driven by this revelation,
she embraced death, eagerly anticipating her rebirth. As prophesied, she
returned as Drupada's daughter, retaining memories of her past life. Upon
encountering the garland, she wore it, triggering Drupada's ire and leading to
her exile.
In the wilderness, the princess encountered a Yaksha named Sthunakarna, who, moved by her plight, offered a solution: a gender transformation, turning her into Shikhandi. In the epic battle of Kurukshetra, Shikhandi, alongside Arjuna, confronted Bheeshma, who, bound by his vow, refrained from attacking. Leveraging this opportunity, Shikhandi avenged Amba's past and fulfilled her mission by aiding in Bheeshma's downfall.