Origin

The bitter feud between the Allen family and the Thawne family would span generations. Even in the 30th century, President Thawne sought to recruit Bart Allen in his revenge campaign against the Allens, since Bart was half-Thawne himself. When that failed, Thawne mixed Bart's DNA with Thawne genetic material to create a speedster clone whom he named Thaddeus Thawne. Wheras Bart grew in a hyper-accelerated world, Thaddeus' childhood was the exact opposite; His development was super-slow, which led the young speedster to become more calculating and methodical. Thaddeus was also taught to hate the Allen family, and Impulse in particular.

After years of indoctrinated hatred for the Allen family, Thaddeus traveled to the past and began to observe Impulse with the help of his technological servant, Craydl. Taking the name Inertia, Thaddeus fashioned a green "reverse-Impulse" costume and confronted the young hero. After meeting with failure, Inertia insisted the first encounter was merely a recon mission; After all, Thaddeus was Bart's superior in every way.

Inertia later ambushed Bart and held him prisoner in a virtual reality, while he assumed Impulse's identity on earth. Once gaining Max Mercury's trust, Inertia led him into a dangerous trap within the speed force, intending to kill him. When Impulse raced to save his mentor, Inertia witnessed the love and trust between the speedsters. At that moment, Inertia realized that his whole life had been dedicated to a centuries-old hatred - leaving his own life cold and empty as a result. Now enraged, Inertia bolted from the scene.

Titans East

In the wake of the Infinite Crisis, Inertia realized that Bart Allen - as the new Flash - had completely co-opted the Speed Force. Jealous that Bart has once again usurped him, Inertia gained super-speed from the speed drug known as Velocity 9. The supplier of this drug was none other than long-time Titans adversary, Deathstroke. In exchange for his super-speed, Inertia agreed to join Deathstroke's Titans East team. As a member of the villainous team, Inertia became romantically involved with the hot-tempered Sungirl.

Titans East set up their own Titans Tower on the East River, the very same location of the old tower. Deathstroke had his own agenda, which was to reclaim his children, Ravager and Jericho. Titans East was nearly successful in that mission, until Nightwing, Flash, Troia and Beast Boy helped turn the tide and reclaim their island headquarters. The members of Titans East dispersed, unaware of Deathstroke's true objective; By cementing his offspring as trusted members of the team, Slade knew the Titans would provide his children with a better family than he ever could.

The new rogues

After failing to defeat Bart Allen by himself, Inertia began to gather a Rogues Gallery of villains to team up against Flash. Meanwhile, Iris Allen returned and warned Bart that if he fought the newly formed league of Rogues, he would not survive. Inertia, in a plan to steal the speed force energy for himself, manipulated the Rogues into battle with Bart. As a depowered Bart fought valiantly against the combined might of the Rogues, he saw the spectre of the Black Flash, and died as Iris Allen and Valerie Perez were left to mourn him.

Powers & Abilities

Super-speed; Ability to vibrate through objects. Thaddeus Thawne is more methodical than Bart, which can give him an advantage in battle.