Kisar

Kisar is a Thijarian, an ancient species of assassins. After his planet was destroyed, and was unable to grieve or honour those who were lost, Kisar and his associate Almak decided to leave their old ways behind, and bear witness to those who died alone. The Thirteenth Doctor, Ryan and Prem accidentally came aboard their hive, where Kisar and Almak was waiting to bear witness to those who died during the Partition of India in 1947. The Doctor was not aware, until later, of their new objective to honour Prem. (TV: Demons of the Punjab)