Complex sentence: Beristain announced that his full name was "Arturo Beristain Ramírez" to keep up the storyline that he really was the son of El Gladiador, it was later confirmed that his last name was not Ramirez.
Split into simpler sentences: Beristain announced that his full name was "Arturo Beristain Ramírez" to keep up the storyline that he really was the son of El Gladiador. It was later confirmed that his last name was not Ramirez.