Complex sentence: The leader of Clear Sky, Lebedev, is amazed by Scar still being alive and therorizes that the Zone is being disrupted by a dramatic increase in energy emissions, emanating from the Chernobyl power plant in the center of the Zone.
Split into simpler sentences: The leader of Clear Sky, Lebedev, is amazed by Scar still being alive. Lebedev begins to therorize that the Zone is being disrupted by a dramatic increase in energy emissions, emanating from the Chernobyl power plant in the center of the Zone.