Board Thread:Fun and Games/@comment-25958552-20160730164841/@comment-31002115-20170109181026

Quick though gaster could of created sans, sans then created a gaster blaster and melted gaster with it while cracking his skull, maybe he created sans a while before papy and sanses heart was melted by a baby skeleton laughing at him while he might of tried to kill him, and ever since he has tried being good

Thats just a quick thought, no time or effort put into that theory