The Eraser was a multifunctional energy manipulator - created by the renowned scientist Tobal Reist of the planet Trionikus.
The weapon was shown as been sentient and 'intelligent' - been able to speak and showing care to its creator. However, the weapon was programmed to obey whoever wielded it - which meant it could easily fall into the wrong hands. It also admitted feeling regret when Horstrogg wielded it after killing Tobal.
The Eraser was extremely powerful - been able to destroy or capture various spacecraft. It was also shown as been capable of destroying an entire planet - as evidenced by the asteroid belt. According to the Eighth Doctor, it was able to sense the artronic aura of his TARDIS and recognize the ship's capabilities.
InformationEditTobal Reist - the most renowned scientist of the planet Trionikus - began to create what would later become known as the Eraser. Tobal's reason for creating the device was to prepare in case Trionikus entered any conflicts in the future.
After completing the weapon and programming it to obey whoever wielded it, Tobal began to prepare to test his new creation. In the first test of the weapon's power, Tobal attempted to use it to destroy a spittoon. However, as clever as he was, Tobal had severely underestimated the power output that the Eraser was capable of. When the weapon was fired, the true extent of its power was revealed.
Trionikus was completely annihilated when the Eraser was fired, with the planet blasted into over 18 billion fragments. Tobal's people were all killed in the planet's destruction, with very little of the planet and the creations of its proud people remaining. As he was at the center of the metatronic flux, Tobal became the only survivor of the catastrophic destruction of Trionikus - with the pieces of the planet that remained forming an asteroid belt.
The Eraser was soon revealed to be more advanced then Tobal had anticipated. The machine showed intelligence and even care towards its creator. To ensure Tobal's survival, the device created a gravity web to hold together one of the large pieces of the planet's remains and also created an atmospheric shell so Tobal could breathe. In the years that followed, however, the combination of Tobal been isolated for so long and his guilt from knowing he was responsible for the near-extinction of his people and the destruction of his home took a heavy toll on his psyche. Referring to the Eraser as his 'friend', Tobal slipped into a delusional state - having forgotten most of his past and believing that he was simply lost and would find 'home' again. The Eraser seemingly played along with this, as it was unable to help in any other way.
When the Qutrusian Cargo Freighter X-703 was thrown off course due to an attack by pirates - led by Captain Grast Horstrogg - the freighter came to a halt not far from the asteroid belt. On-board the freighter, the Doctor and his companion Izzy had also accidentally arrived. The Eraser detected the two ships and, seemingly at the request of Tobal (who had developed a dislike of fighting and so had automatically decided he didn't like the pirates), the Eraser open fired on the pirate's ship - completely obliterating the vessel. However, the Eraser soon detected the artronic aura of the Doctor's TARDIS and recognized its capabilities - possibly intending to either use the machine to simply get Tobal to another location or possibly go back in time and avert the destruction of Trionikus.
Using its capabilities, the Eraser attached an 'energy leash' around the freighter (which was unable to move due to the pirates having crippled the engines during their initial raid), before carefully drawing it through the asteroid belt towards the large asteroid that Tobal was on. After landing the freighter on the asteroid surface, the Eraser ripped through part of the freighter to the cargo bay where the Doctor had landed the TARDIS. Using the same energy leash technique it had used to capture and bring in the Freighter, the Eraser captured the Doctor's TARDIS and brought it to Tobal - who was delighted that he would finally be able to 'return home'.
When the Doctor and Izzy learned that the TARDIS had been stolen from the freighter, the two of them headed off onto the planet surface - joined by a friendly Cyberman named Kroton who they had encountered aboard - with the Doctor using a device he had to locate the TARDIS. Upon finding it, the trio were understandably surprised to find Tobal singing and dancing. Trying to learn more, the Eraser reveals itself and explains its creation as well as the identity of Tobal and the destruction of Trionikus. The Doctor kindly offered Tobal a ride, but the conversation was interrupted by the arrival of the pirates - who demanded that Tobal hand over the Eraser as 'repayment' following the destruction of their ship.
Kroton, however, responds by fighting the pirates. As Tobal tried to stop the fighting, he was shot in the back by Horstrogg - killing him. As the Doctor tried to stop Horstrogg from taking the Eraser, the former military officer easily knocked the Doctor aside - but was soon forced to pursue him as the Doctor had stolen the power cell for Horstrogg's transmat. Giving up the chase after the Doctor had hidden away, Horstrogg talked to the Eraser and declared to it that he was its new captain - to which the Eraser revealed that it has "regrettably been programmed to obey whoever wields it".
Overhearing this, Izzy made a decision (which she admits to herself that it wasn't a wise one), as she leapt out and managed to grab hold of the weapon before ordering it to destroy itself in order to prevent Horstrogg from having it. Before Horstrogg could stop it, the Eraser obeys Izzy and self destructs.
Following the destruction of the Eraser, however, both the gravity web and the atmospheric shell it had constructed for Tobal both begin to collapse - with many of the pirates possibly been killed or thrown outside the atmospheric shell as the asteroid they were standing on broke up. Working together, Kroton, Izzy and the Doctor managed to get back to the TARDIS and headed off, while both Horstrogg and his first mate Mr Shakka (who both survived the break-up of the asteroid) were left behind on two separate pieces of the asteroid - arguing with each other as they drifted apart.
The Company of Thieves - Comic