The thought of winning against Amir made him so eager that when Zara told him of her request, he didn't hesitate but comply.
"There is something that I didn't tell everyone before. To remove the curse, I need blood from the person who loves me, cares for me, someone I love dearly and have been with for the longest time."
Hearing such a long confession, at least for him the part where she said someone I love dearly, how could he not do what she wants?
The truth be spoken, Zara loved him. He didn't know if it was the brotherly love or the love between a man and a woman, but he knew that she had feelings for him.
If circumstances did not force her, then maybe it would have been with her right now, and not Amir.
Unfortunately, after cutting his palm, he didn't feel well at night, so now he could accompany her to protect her during the ritual.