Many have pointed out that very few metals actually burn, and none would be good for top-of-the-line robot creation. So why do they burn???

My theory is that the energy that powers all the robots in the form of atomic fusion plasma is being driven over its melt-down temperature and released from its container from external sources (swords or hammers) and creating a chain reaction of varying strengths depending on the initial disruption temperature.

Basically, their fuel catches on fire and incinerates them from inside!

my theory is FFFFFFFFFFFFFFFIIIIIIIIIIIIIIIIIIIIIIIIIRRRRRRRRRRRRRRRRRRREEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I think I've mentioned this somewhere else, but my theory is that the fire effects and the damage itself are from different sources, the former being from flammable components (those made from plastic, silicon [I think], etc.), the latter from the metal of the robot actually melting (rather than burning). Assuming the "laser sword" is formed from magnetically suspended, superheated plasma, I think it makes sense for it to transfer a massive amount of heat to the robot on impact, inflicting the damage and fire effects.