This is a big spoiler!!!
Yes, Faraday is the son of Widmore & Eloise. Faraday arrives back to the island by sub. He tries to get Chang to evacuate the island by telling him the truth about the island and Miles. He ventures into the Other’s camp to talk to his mother who shoots and kills him prior to talking to him.
Eloise is not portrayed as a villain because she doesn’t know (at the time she kills Faraday) he’s her son. She learns of his plans through Jack and Kate, and tries to see them through with the help of Richard.