When Fang Lei first went into combat, he brought Thor’s Hammer with him. But Fang made a mistake that was to prove tragically fatal. “We forgot to assemble one of the parts,” he said.

A heavily armored robot developed by Fang’s team, the Mr. O. Robot Fighting Club, Thor’s Hammer’s defining feature was, indeed, a hammer-like weapon worthy of a robotic Norse god. Its thick armor might have been able to deflect the worst effects of its opponent’s horizontal rotating blade, but the team had a more pressing problem to contend with.

“Our robot was over the weight limit, so we had to remove the armor on the sides,” Fang said. By the time the match began, the hammer was gone too—due to technical trouble—leaving a robot with no protective plating and limited avenues for attack. “As a result, our wheel was broken by our opponent and we lost all the matches after that. We felt heartbroken,” Fang said.