Skynet had determined that it could never defeat the humans, so it decided to have humans defeat the humans and it went back in time as far as it had the energy to do so. It created a Japanese T-800 and sent it back to the year 1629. Despite the high risk of it gaining self-awareness and independence, Skynet sent this Terminator out with the most intelligence of any Terminator before it.
Its mission was to conquer Japan and become emperor. Even the finest Japanese sword could not do any damage to the Terminator's endoskeleton, but fire could destroy its flesh. After many fire attacks, it was exposing its metal face and body.
If mankind knew it were a machine, then they would know it could be destroyed. It, therefore, convinced everybody that it was a demon. After 100 years as emperor, it created a great army and navy to conquer the world.
Skynet was wrong to make it too intelligent because it created its own agenda. After it dominated the entire world, it would make gun powder, guns, and any other technology that could help humans develop a means of destroying the now King of the World illegal and eventually forgotten. The entire world was for the first time one. One language, one culture, one King.
Without industry or nuclear power, its power cell would eventually run out and it would die. It would sit on the throne for sometimes years without moving in low power mode, preserving its energy and letting the well-trained generals and diplomats deal with the world.
By the time the year 2179 came around, the Terminator King was very low on power. The entire world was Japanese. No internet, electricity, combustion engines, or explosives existed. Skynet would never come to be. Knowing of mankind's ingenuity, the King knew he had to destroy himself or they might reverse engineer him in a few hundred years, so with one percent power left, the King jumped into an active molten volcano destroying Skynet forever. 終わり