He doesn't need food, but as long Xie Lian carries his ring on him, and like every voidtrekers, as long they are tethered to the train, then he has the reason to exist. Hua Cheng appears to have a bottomless pit of a stomach, unaffected by his toxic cooking, so he is fine and he looks into the food pantry for sweets and finds a red apple which he cuts up into neat slices and appears to be eating when he munches.

"I think we help a lot gege, by helping others. From what I learned from my butterflies, the train pulls people from different worlds to live on-board. There's several purposes, but the main reason and mission is to save worlds. Like this one, it seems the world is preparing itself with the help of robots, the Helpmates to be a colony. That might explain why there's a lot of empty houses and animals, but no people."