Trask created a prototype called Master Mold who then create Mark I Sentinels. However, the Sentinels' logic decided that if they controlled the humans, they would take care of the mutants. It captured Trask and he realised that he was the one who had created the threat. To destroy Master Mold, he sacrificed himself by triggering an explosion.

The Master Mold repaired itself and continued its attempts to eliminate mutants.

At the aftermath of one such battle, the future-Sentinel Nimrod came in contact with a fragment of Master Mold-s circuitry and was taken over by it. However, the Master Mold now, in effect, contained two separate intelligences: that of he Mold itself and that of Nimrod. Suddenly, the combination of the Master Mold and Nimrod could detect the presence of the X-Men. Nimrod's intelligence contended this was because the Mold and Nimrod had somehow "mutated" and become a "living being." (Exactly what this means is unclear as yet.) Since the Master Mold was intent on destroying mutants, Nimrod now urged it to fulfill its prime directive by destroying itself, While the Mold-Nimrod synthesis was thus debating with itself, the X-Man, Dazzler, unleashed an energy blast that propelled the Mold-Nimrod creature through the dimensional portal contained within the mysterious Siege Perilous crystal.He reemerged as the human/sentinel hybrid Bastion. He still maintains his hatred for mutants.

Powers

The Master Mold is the most advanced Sentinel other than Nimrod. It can repair itself by integrating any metals or mechanical systems around it, project energy blasts, and interface with computer systems. It can reconstruct itself at a variety of sizes and create internal weapons systems and scanners to detect mutants. It can hide multiple copies of its program and activate them if its main memory is destroyed.

• Characteristics *
  

Height: Variable, ususally 30'

Weight: Variable, depends on availlable materials

Eyes: Yellow

Skin: Depends on the materials present, but usually grey