Proconsul Derrimus Kalistine governs the Serrofus planetary system on behalf of the Imperial Combine, from the annexed world Serrofus Major. He is an uncompromising and ambitious ruler, with xenophobic tendencies which he does little to hide.
Kalistine's wish was that — under his leadership — Serrofus Major would become the major cultural and production centre of the empire, rivalling Damastion, Ramm Stallahad, and Maidre Shalleon. He was quite prepared to trample on the indigenous Mastalekt to achieve that goal, and used a narrow-minded and perhaps even bigoted interpretation of the rules of governance while pursuing it. One of the first phases in his plan was the clearance of the meadows, a huge area of fertile land adjacent to the capital in which grew vast quantities of a plant considered sacred by the Mastalekt.
It was Kalistine's tendency to favour humans over the Mastalekt which the entity known as Voice sought to exploit for its own ends. Using the Rasa infiltrator Herik Pammon, Voice recruited the unwitting Maber Castigon as well as a man named Collis. It then had both men orchestrate the intensification of racial tensions in the capital city of Serrofus Major (→LOTD).
As a result of those tensions the capital was sacked, and Kalistine's House of Governance was breached by an angry mob. Shard Jidian Tarrow and her counterpart Miall Crathus evacuated Kalistine through a secret tunnel, taking him to the supposedly secure bowels of the city's commerce hall where unfortunately the vengeful Castigon was laying in wait for Tarrow (→LOTD).
As well as allowing Castigon to complete his objective of killing the Shard, which Kalistine witnessed, the civil unrest which resulted from these actions helped to advance Voice's plans directly. Just as Voice intended, Kalistine became incredibly aggressive in his efforts to pacify the population, and gratefully accepted several full battalions of MAGA troops on the surface of his planet. These troops were later the target of an attack which spread the Rasa virus on the planet, greatly swelling the size of Voice's standing army. It is not known if Kalistine was one of those affected by the virus, or even if he is still alive on the planet's surface (→TRD).