Quinlan Vos
Blink and you’ll miss him, but Jedi Master Quinlan Vos also appeared in Star Wars: Episode I. Ironically the character started off as an extra. Notwithstanding, Star Wars producers like his visual look so much they used it for the Quinlan Vos character. It’s said that he was working undercover on Tatooine at the time of The Phantom Menace.
Of the prequel characters mentioned here, Vos has one of the most compelling stories. He’d appear in The Clone Wars animated series alongside Obi-Wan Kenobi. Later, he turn to the Dark Side and back as he’d pair with Asajj Ventress in an effort to topple Count Dooku in the novel Dark Disciple. Rumor has it he survived Order 66, but alas, his fate following the Clone Wars: Unknown.