Complex sentence: The Merovingian is the leader of a group of Exiles, employs The Twins and others as his henchmen, held the Keymaker prisoner, and controls the Trainman.
Split into simpler sentences: The Merovingian is the leader of a group of Exiles, and employs The Twins and others as his henchmen. He also holds the Keymaker prisoner, and controls the Trainman.