The Legend Begins

Ben is on his way to Rook's going away party. During the party, a villain named Dark Matter, a villain from an alternate dimension, attacks. Ben must team up with the Omnnitrix wielder from that dimension, the only person left alive of that dimension, to defeat Dark Matter.

Plot
To Be Written

Heroes

 * Ben Tennyson (First Reappearance)
 * Kennedy Tennyson (First Appearance)
 * Rook Blonko (First Reappearance)
 * Grndpa Max (First Reappearance)

Villains

 * Dark Matter (First Appearance)
 * Maltruant (Cameo; First Reappearance)

By Ben

 * Diamondhead (First Reappearance)
 * Four Arms (First Reappearance)
 * Clockwork (First Reappearance; Cameo)
 * Swampfire (First Reappearance)

By Kennedy

 * Omnistar (First Appearance)
 * Seed Weeder (First Appearance)
 * Speedraptor (First Appearance)

Trivia

 * Tis is the first episode of Ben 10: Twin Omnitrixes.