Last Monitor

Duke Thomas was once a sidekick to Batman, training under him to become a protector of Gotham City. He would be the final pupil of Batman, however, as the hero was used by the dark dragon Barbatos as an entry point into the multiverse. As Barbatos turned Batman into his vessel and the Justice League into his dragons, Duke watched his world collapse around him. Knowing his own world was without saving, Duke decided to flee into the multiverse, hoping to save at least one world from Barbatos' "Deathwave".

For two years, Duke outran the wave, doing everything he could to stop the wave or save the other 51 worlds, failing all the same. During this time, he discovered his powers to see visions of the past, and stole armor that allowed him to more freely traverse these worlds. When the 51st world collapsed, Duke, now called the "Last Monitor", had nowhere to go but back to his home. When he arrived on "Earth-Metal", Duke encountered his former teacher and his monstrous allies. He attempted to fight them, but would have lost had his old friend Nightwing not saved him. Duke followed Nightwing back to his lair in the Justice League Watchtower, where the world's last heroes, like Hawkgirl and The Flash hid. Despite knowing the Deathwave was coming, Duke gathered the heroes into a new Justice League, hoping for one final victory for good, before the end of everything.

After freeing a dragon of their own from the Batman Who Laughs, the Justice League faced off against the Dragons of the Bat. Duke's teammates gave their lives to stop the monstrous army, leaving him alone to battle his former teacher, now a monster called the Dragon of the End. Despite the Dragon's incredible power, Duke managed to survive its attacks long enough to teleport inside it, where Batman's original body laid dormant. Duke cut the tethers between Batman and the rest of his new body, killing him, leaving Duke as the last being alive while the Deathwave collapsed around him.

In the multiverse's last moments, Duke crafted the Dragon's skin into a new armor, and took Nightwing's Parall-Axe. The Final Knight watched as existence crumbled around him, and used his teleportation belt one final time. He traveled into the Dark Multiverse, where he encountered an observer named Tempus Fuginaut. Enraged that the being watched his world die and did nothing, the Final Knight knocked him out, before leaving into the Dark Multiverse once more, as the lone hero of countless twisted worlds.