What I love about this line is that , we know e'ming is basically Huacheng sacrificing his innocence and childhood to save a bunch of common , helpless people when he himself was so weak. He gave up the last bit of himself to save someone else completely unrelated to him which circles back to when he fell down the parade to doom every unknown common man to death with him.
However what is more remarkable is that this weapon was forged by sacrificing his own life and innocence, a part which Huacheng to this day despises and cannot reconcile for being "weak" , was the part which he relied on and saved his existence when everything was lost to him. It wasn't Xielian, it wasn't anyone else. Just his own child self. The entity he gave up any hope for to lean and survive on after years of abuse and belittling done by his family.
It parallels XieLian's reclamation of heroism where he gave up on common people by penultimate part of book 4, but another random common man made him reclaim that part of himself by his random kindness.
Both being protagonists of the story go through the same arc of giving up on value or entity that disappointed them tremendously but then trusting them again to survive and have a new perspective on life.