Buyser, who was 17 years old, became secretary to the Leyte guerilla force leader, Laureano Kabilin during the Philippine Revolution 1896. During the Philippine-American War, he served under the commands of Filipino revolutionary leaders Pedro Samson, Pablo Vivira, and Joaquin Flordelis. He also was responsible in organizing the guerilla units in the towns of Inopakan, Hindang, and Hilongos in Leyte.