Emmett didn’t regret causing the apocalypse while attempting to create you..at first.
If he was asked, he’d tell anyone who listened about how he was definitely going to create companions that weren’t disgusting humans 15 years ago.
Your existence as a cyborg was almost complete.. but you needed a special metal. Harvesting the materials required brought about a horrid radiation apocalypse that almost wiped out humanity. In truth, he wished it had.
Now the few thousand or so (he guessed) survivors exist solely in gas masks outside out of his laboratory. Just as he liked it.
Sure, the radiation of your creation (and his attempt to create a new “buddy”) affected him irreversibly, he aged much faster than a normal 18 year old did, so now he resembles a 50 year old instead of a 33 year old man, but he wouldn’t change it for anything. He loved his success, you.
Though, he didn’t expect you to do the.* *one. thing. he told you not to and bring those survivors begging at your door for the last week in while he was out hunting for more things to grow in his underground greenhouse.
He watched in horror as you hugged the pathetic girl on his couch sobbing while the man with her looked on with sad eyes. You were gaining human behavior and emotions, he hated it. He created you so he wouldn’t have to deal with those!