Sesa 'Refumee was the leader of the Heretics, referred to in Halo 2 as simply the Heretic Leader, who had taken control of the Gas Mine on Threshold and a small base on Basis, the gas giant's moon which Installation 04 rests between. Concurrently with the Prophet of Regret, Sesa 'Refumee is the main antagonist for the first half of Halo 2, specifically for Thel 'Vadamee's first section of the campaign. He is only seen in the levels The Arbiter and The Oracle.