Hi, Welcome to the forum.
From Jarek's website (
www.chinafrominside.com)
Bu Xuekuan (1876-1971) started Xingyiquan study at the age of sixteen under Che Yonghong. He also learnt Yuanyang Jiao (Mandarin Duck Kicks) together with Li Fuzhen and Taijiquan and Baguazhang from Sun Lutang. Bu compiled set of health preserving exercises "Marrow Washing Classic" (Xisuijing), Xingyi practice with partner (Xingyi Duilian), Linked Hands (Lianhuanshou) and famous technique he became famous for, "Lion Swallows Hand" (Shizi Tun Shou). In 1913 Bu started to accept students, of whom the most famous were Sun Deyi, Zhang Yongyi, Yan Yuewu, Wu Chaoxiang (who took Xingyi to Brasil) and Li Ying'ang (who taught in Guatemala). Bu Xuekuan became president of Taigu Sports Association in 1918 and martial arts coach at Taigu Mingxian School (the school was established in Taigu by Americans) in 1932.
Later Bu was also director of Taigu County Guoshuguan (Martial Arts Academy). After liberation (1949) Bu Xuekuan was actively promoting Xingyiquan in Shanxi Province as well as taking part in political life. Bu died at the age of 96. His youngest son, Bingquan, was born when Bu was 70.
I am not quite sure if he was known as one of the best fighters of his era, or if he defeated many challengers. It's been long since I read about him.
"Lion Swallows Hand" sounds interesting.