On his return to Peru, Felipillo continued serving as a translator for the Spanish as the conquest of country carried its course, although historians agree that the interpreting provided by Felipillo was far from faithful or even helpful for the Spanish. After Francisco Pizarro captured the Inca Atahualpa during the Battle of Cajamarca in 1532, Felipillo was the main translator for Pizarro and Atahualpa during their first meeting. Since Felipillo belonged to a rival tribe and was having an affair with one of Atahualpa's concubines, he deliberately translated Pizarro's messages in an inaccurate manner to the Inca king, which led Atahualpa to speak in unflattering terms about Catholic doctrine, the Bible, and the whole Spanish presence in his land.
In another incident, Felipillo betrayed Almagro during his expedition of Chile by secretly telling the local natives to attack the Spanish since they only wanted their gold and urged them to attack them or run away. Some accounts say that when Almagro found out of Felipillo's betraying motives and his confession about purposely misinterpreting Pizarro's message to Atahualpa, he ordered his soldiers to capture Felipillo and tear his body apart with horses in front of the region's curaca (tribal chief).
Nowadays, among Peruvians, the word "Felipillo" has taken a meaning similat to "traitor."