AMBA

She was the daughter of king of kashi and the sister of ambalika and ambika. She reincarnated in the form of shikhandi and was the cause of Bhishma pitama's death

AMBA
Amba and her sisters were taken from their  swayamvar  by bhishma as wives for his brother Vichitravirya. Amba told Bhishma that she wanted to marry the king of Shalv. Bhishma agreed and she asked the king of Shalv to marry her, he refused saying that he would  not marry her as she had been taken to another king , and it woul be against his honor.So amba went to bhishma and asked him to marry her to vichitravirya. Vichitravirya also refused, so Amba was travelling from one kingdom to another begging one of them to marry her , bothe refused , fed up she jumped into flames and pledged to be reborn as a man and be cause of bhishma's death.