Complex sentence: Jango takes part in the Battle of Geonosis, where he first encounters a beast known as a Reek which tramples and damages his weapon systems, he then is decapitated by Jedi Master Mace Windu in open combat, which his son Boba witnesses.
Split into simpler sentences: Jango takes part in the Battle of Geonosis, where he first encounters a beast known as a Reek, which tramples and damages his weapon systems. He then is decapitated by Jedi Master Mace Windu in open combat, which his son Boba witnesses.