Original: Malcolm "Mal" Reynolds (Nathan Fillion) is the owner of Serenity and former Independent sergeant in the pivotal Battle of Serenity Valley.
Simplified: The captain of the crew of Serenity is Malcolm "Mal" Reynolds (Nathan Fillion). Malcolm "Mal" Reynolds, played by Nathan Fillion, is Serenity's captain and former sergeant in the Battle of Serenity Valley during the war.