not sure what this had to do with the prequel, but you painted a vivid character, then killed him off so suddenly. the ending sounds great, but i am not sympathetic to the robot metal elemental very much. I thought this was more about the fire boy than the metal.
Pitting these two soundly different characters against each other in a narration such as this was well-imagined and well-executed. You’ve set up an intriguing story.