That Time I Was reincarnated as King ghidora

(backstory summary) a time before he was the golden devil, he was a 16 year old boy named Kevin he was abandoned at age 10 by his parents He spent 6 years alone with no reason to him everyone seemingly hated him. He is only seeing the worst of humanity to offer. One day He breaks into a warehouse unknownly that was full of guns that are going to be sold illegally. finding one of the guns stealing it and goes hunting for his family that abandoned him so long ago. when he finds them he kills them and He runs away from the crime scene trying to put back the gun so no one gets suspicious for The crime. One of the members of the group He stole from he is immediately shot and was killed. Unlock the for us he meets the being of void. Hold up. How do you know this origin. Are you sure about it? I do very much because I am the golden devil.