Sans gets struck by lightning and becomes Fanon Sans

Sans was asleep in an open field when it started to rain. He continued to sleep in the rain for hours.

If you didn't know him very well you might think that was because he hadn't noticed. Not so. He had read the weather forecast, and he woke up and turned over a few times. He just liked rain.

Something that had slipped his mind due to inexperience was lightning. There was a kind of rain in the underground, but there was no kind of lightning. A lightning bolt hit him straight in the eye socket.

Nothing visibly happened for a few seconds, while whatever it is skeletons use to think reconfigured itself in his skull in some inscrutable manner.

Sans jolted awake, covered in sweat, and let out a cry. "oh no! the resets!" His eye flared blue, and he shortcutted away.

Papyrus was doing the dishes when Sans appeared. "Sans? Where did you come from?"

"tibia honest, i'm not sure," said Sans nonchalantly. "where is Y/N?"

"'Wye slash enn?' Is that an abbreviation?"

"unless.......the fucking kiddo!!!" Sans shouted and shortcutted away again.

Frisk's room was quite peaceful. Until Sans teleported in and tried to slam Frisk against the walls and ceiling (but instead targeted a conveniently shaped nightlight due to his blue magic-induced poor eyesight).

The resulting ruckus woke up everyone in the house. Frisk was still groggily staring at the mess Sans was making when a very upset Toriel walked through the door.

"Sans? I do not know what you have been drinking, but you need to leave."

"no!!" Sans cried. "my secrecy and depression ruined my romantic relationship!!" Then he shortcutted away.

"i have to go back....before the reset," he muttered to himself when he arrived in the CORE. "i can use this time machine.."

He walked up to the main transformer and firmly grasped it with both hands. The shock knocked him out, and he slept peacefully on the ground. He was found four hours later during routine maintenance, back to old with a short gap in his memory.