The Rise of Civilization

[First planet has reached the threshold. Main Quest 2 activated: Rise of Civilization]

Details: From a planet of boiling magma and chaotic astronomical forces vying for dominance, you have built a world that has the makings of stability. As your first primary lifeform, Modified Saiyan, develops, you will need to make their eyes point towards you, their source of life. 

Task 1: Using any means necessary, convince your population to show reverence towards you or your primal forces.

Rewards: Three primal forces based on the core traits of saiyans and humans: Willpower, Intelligence, and Emotion

Task 2: Any group of saiyans begins to form cities.

Rewards: 100 SP per city

Task 3: Total population of sentient life exceeds 1 million

Rewards: Avatar Coupon

Task 4: Any civilization begins using metal tools

Rewards: 1,000 SP

[Quest Details end]

"Wait a second. Didn't those first two already happen?"

[System Clarification: Ecruteak Village is not a city, but a tribal dwelling. Cities are distinguished by having a strong central authority and structure of government, not just a few elders and a chief.]

"But what about the first one..."

[...]

"System?"

[Rewards distributed: Please design your lifeforms.]

[Notice: Please do not create myths based on destruction. Don't become a tyrannical deity.]

Sadalla would have facepalmed if he had arms to do so, but his current forms didn't possess arms, as his form of Zygarde was spread out into a mix of several cells, a few cores, and a single snakelike creature formed of around half of the cells and one core. 

"Let's just make them little yellow-eyed pixies with two tails. Give willpower a blue colored face, Intelligence a yellow face, and Emotions a pink face."

[Lifeforms created: Unnamed pixies (3x)]

Sadalla was miffed about being called tyrannical. It's not like the planet would survive without rain and storm. Storm deities and other weather-based deities were practically the firstfruits of the human mind anyways. At least this one had a happy ending.

Over time, civilization did eventually develop. Despite the horrifying environment filled with dangerous creatures, the saiyans did manage to develop. Many so-called lesser legendaries were created, like Heatran, Cresselia, the Djinn trio/quad of Landorus, Tornadus, Thunderous, and Enamorous, and the horse-like Swords of Justice. Cities developed in the Yamato island chain, along the various edges of the North Sea, China's east, Australia, parts of the Americas, India, the area around the Mediterranean Sea, and several other regions.

The most important of these peoples to Sadalla was the Celestica Civilization on the northernmost island of Yamato, which had to deal with an incident involving Dialga, Palkia, and Giratina, which is what they named the fourth, third, and first dragons respectively. They strangely didn't consider Arceus, their name for the second dragon, to be a dragon at all. Sadalla was intrigued, and he discovered why by getting one of his cells closer to the Celestica people. He learned that the people of this world, who strangely called themselves humans, had divided the creatures they encountered into eighteen separate types, based on the energy they used in attacking or defending. Arceus was considered type-less, or "normal".

Sadalla was amazed by this theory, which he termed the "Theory of Natural Energy". To him, this explained a lot, and by tuning Zygarde's body to try and sense this energy, he discovered that it could possibly be considered a kind of magic. His avatar, Zygarde, was primarily composed of an energy from the ground and an energy primarily seen in draconic and reptilian creatures. He detected that his body could also use other natural energies, but with less efficiency. 

Though Celestica was important, it wasn't the place that mattered most to him. In Mesopotamia, a land between two rivers known as the Tigris and the Euphrates, a civilization developed five thousand years prior to Celestica. They were called Sumerians, founded by a man named Sargon of Akkad, who conquered several fortified cities to form the Sumerian Empire. It was the rapid expansion in this region, known as the Fertile Crescent and the Mediterranean Basin, that accomplished Sadalla's remaining tasks.

[City: Ur, Sumerian, has been founded] [City: Heliopolis, Egyptian, has been founded]

[City: Uruk, Sumerian, has been founded] [City: Dur-Sharippa, Hittite, has been founded]

[City: Babylon, Babylonian, has been founded] [City: Mohenjo-Darro, Indian, has been founded]

[City: Knossos, Minoan, has been founded] [City: Mycenae, Mycenean, has been founded]

[City Heliopolis has begun manufacturing metal tools] [City: Nineveh, Assyrian, has been founded]

(None of that is historically accurate in timescale, but since the Celestica civilization is active around 100 BC, I just stuck a bunch of cities from the Bronze Age and Iron age here. There were literally hundreds to thousands of cities in the region, and plenty more around the world.)