Marcus Langston was the leader for Youngblood's Away Team. Marcus had no superpowers but used his intellect and suit as his power. Lost his right eyeball in combat.
In the miniseries Judgment Day, it was revealed that Marcus owned the Book of All Tales. a magical book that could alter reality and change people's fates. Marcus' fate was originally he had been headed for an early death as a thief, but he rewrote his destiny inside the book to make himself a superhero of an increasingly violent world. When Youngblood teammate Riptide discovered that Sentinel stole the book from her father, Storybook Smith, Sentinel murdered her and framed Knightsabre to cover his tracks. The truth behind Riptide's murder was eventually revealed in superhero court when lawyer Toby Tyler discovered the book at his home and was taken into Supreme's custody in the Hell of Mirrors at his Citadel Supreme.
Alan Moore's Youngblood
Sentinel eventually escaped along with Supreme's rogues Televillain, Korgo, Shadow Supreme, Slaver Ant, and Vor-Em. Sentinel wanted to reclaim his leadership of Youngblood after his shame and when he discovered that Waxely Doyle is now funding the new Youngblood team, Sentinel formed Badblood consisting of Lounge Lizard, Satana, Speedwall, Poppy and Atomo to destroy his former team. They almost succeeded until Waxely came to the rescue.