What kind of pronoun does an omniscient narrator use?

No, an omniscient narrator tells a story in the third person.

A first person narrative from personal experience:

I've worked in the audio book industry for 9 years. I just finished editing a book that started out with an omniscient POV. The narrator described the emotions of every character. Pace and timing is key to good editing. I was in a rhythm. The narration I molded was smooth with no breaths, palate/lip clicks or emotions. He moved the story along as if the Words were being thought not heard. Then, he threw in the pronoun "I". What the heck! I was confused. Who was he representing?!

Having done so many audio books I suggest that authors read their story out loud and get an editor.