He is Teletha's older twin brother and a high-ranking member of Amalgam. He is the series' primary antagonist and an arch nemesis to both his sister and Sousuke. His personal Arm Slave is Plan-1055 Belial. He is a child prodigy and a Whispered. Within Amalgam, Leonard is known as "Mr. Silver" and is part of the upper circle. It is understood that his superior Whispered intellect has both generated and proliferated the organization's Arm Slaves, Lambda Drivers, TAROS and other Black Technology weaponry.