Complex sentence: Little is known about the Heretic Leader seen in Halo 2, though it can be assumed that he or someone he knew recovered 343 Guilty Spark from the wreckage of Halo 04.
Split into simpler sentences: Little is known about the Heretic Leader seen in Halo 2. Though it can be assumed that he or someone he knew recovered 343 Guilty Spark from the wreckage of Halo 04.