A month before his death he received the appointment of Vice-Commissary Prefect. Señan was familiar with the language of the Indians, and his reports and mission entries are distinguished by their exactness and beauty of penmanship. Though a very zealous missionary, Señan loved retired life. He disliked to hold office or give orders, and it is for this reason he was sometimes nicknamed "Padre Calma." The Commissary-General of the Indies directed him to write a history of the missions, and Señan in 1819 promised to comply, but he left no papers on the subject. His remains were interred in the church of the San Buenaventura Mission.