Stromling Mechs, originally known as Maelstrom Mechs, are former Assembly Defense Robots corrupted and reprogrammed by the Maelstrom into elite enemies. Assembly Defense Robots were originally designed by Assembly to act as security mechs for the Paradox Research Facility. However, an explosion of Maelstrom energies created by the Spider Queen overwhelmed and corrupted most of the Defense Robots into Stromling Mechs. Only two Defense Robots, PRDX-7 and PRDX-4, are confirmed to have escaped corruption, while their brothers march across the Avant Gardens battlefield.