Modified and retrofitted from a Raythean Challenger Hellcat six-wheeled robot by Closure with assistance from Mayer for use by Rhodes Island as a "kamikaze robot," THRM-EX (short for "Thermal-EX") has a masculine A.I. that, like his "brother" Castle-3, is – again – programmed to adore his creator when not performing its tasks. However, THRM-EX is known for usually showing a great degree of enthusiasm even amidst the heat of battle – as if he is, literally, on fire.