The sentinel is described as one of the "main baddies". The story of the Sentinel, is that there was a brutal Mayan king that was about to die, he wished for immortality and unimaginable power from god for his throne, he got just that. The Sentinel looks like a Dura but has armor like a king. Blinded by rage, the Sentinel hunted and killed every last person living in Lost City.

The Sentinel standing at a pose