Who was the youngest king to ascend the throne in Vietnamese history and defeated the Champa army twice?

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Le Nghi Dan was the eldest son of King Le Thai Tong and Mrs. Duong Thi Bi. He was born in June 1439 and in March 1440 was made crown prince. At that time, Mrs. Duong Thi Bi was especially loved by the king, so she became arrogant, so everyone hated her. The king did not like her behavior and immediately demoted her to Minh Nghi (a low rank of the king's wife).
She did not correct her mistake but openly resented it. King Le Thai Tong was angry, thinking that with such a mother's temperament, the child she gave birth to would not necessarily be a virtuous person, so he demoted her to a commoner and issued an edict to the world that the position of crown prince was still undecided. Her son Nghi Dan was deposed and reduced to the position of Lang Son king.
On June 9, 1441, Nguyen Thi Anh gave birth to Bang Co. When Bang Co was 1 year and 6 months old, he ascended the throne and became King Le Nhan Tong. The royal family's position and hierarchy were then decided. But Le Nghi Dan still secretly harbored other thoughts, especially when there were rumors that Nhan Tong was not the legitimate son of King Le Thai Tong. According to Dai Viet Thong Su, Nhan Tong thought Nghi Dan was his real brother so he did not take precautions.
According to Vietnamese historical anecdotes, Le Nghi Dan gathered more than one hundred trusted subordinates. He also had internal spies in the court, namely Le Dac Ninh, Pham Don, Pham Ban and Tran Lang. On the night of October 3, 1459, Le Nghi Dan decided to start the king's execution. He and his subordinates climbed the wall and sneaked in to kill the king.
The next day, Le Nghi Dan killed Mrs. Nguyen Thi Anh and some others, then declared himself king. At that time, the mandarins such as Do Bi, Le E, Le Ngang, Le Thu... were all angry, secretly discussing the overthrow of Le Nghi Dan, but unfortunately the plot was exposed. They were all killed by Le Nghi Dan. The treacherous and flattering people had the opportunity to run rampant. On June 6, 1460, other mandarins such as Nguyen Xi, Le Lang, Dinh Liet, Le Niem, Le Nhan Thuan, Le Nhan Quy along with many generals and officials unanimously killed Le Nghi Dan and his close associates. The court welcomed Le Tu Thanh back and established him as King Le Thanh Tong.
Thus, after less than a year on the throne, Le Nghi Dan was overthrown by a high-ranking official. History books often do not consider him the legitimate monarch of the Later Le Dynasty.
Nguyen Khac Thuan discussed in Vietnamese historical anecdotes: "Killing the king is a serious crime against the country, killing a brother and killing people in general is an unforgivable crime, using cunning and flattering people is trampling on the conscience of loyal people, living like that is even humiliating to be buried in the ground, how could one dare to sit on the throne"?

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