The word rang out in the empty atmosphere and the comets started crashing down. One. Two.
She stopped at five. There was enough hydrogen now and enough water to start the real work. She gathered moisture in the palm of her hand and breathed upon it.
DNA was complicated -- twisted helixes and complex, handed proteins -- so she didn't start with that. Not yet.
First, she would need oxygen.
Her first attempt at chemotrophs was an abjet failure. She looked up at him sharply, suspecting him of having messed with it like he had messed with her rock. He held up his hands. She breathed out and tried again.
Her second attempt at least did what it was meant to do, processed CO2 into O2, but it was inanimate. It was something that helped, but it is not something she needed.
She relented and started twisting molecules into proteins and proteins into DNA.
When the first bacterium became the first bacteria, he nodded approvingly.
"Why don't you do it?" she asked. It sounded more accusatory than she had expected it to. She wondered if now that there is an atmosphere and she spoke through sound waves, the physical acoustics were distorting her words.
"This is your world," he said.
She sighed. So it was.
She was a Shaper, a one-woman terraforming machine. Objectively, it was terrifying, the power she had.
Subjectively, it was still terrifying, but in an entirely different way. She could burn herself out, building this world, and then her master would have to finish the work for her; worlds could not be left half-unformed.
When the relativistic ships would arrive, a generation and millions of years after their departure, the world had to be ready for them.
Her master had built a world before, so his power was all but spent. Perhaps he would burn out too and the ships this world was meant to welcome would have to keep going.
She would not allow that to happen. Not her death, not his, not the ships sent back into the dark.
She focused again on the bacteria, guiding them on the next step of their evolution. Soon, she would need to bring in oxygen, breathable air.
CO2 to O2.
It would kill 90% of what was currently living on the planet.
At least, that was how it had been on Earth. This was not Earth. Perhaps she could do things differently.
She reached out -- with her mind, mostly, but the physical motion served as a focus -- and twisted. It was not an easy thing and it burned through more of her power than she had hoped -- but still less than she had expected -- but she managed.
There would be no great extinction event once the air turned to second-majority oxygen.
They were granted enough power for terraforming and one big change, if they wanted -- and power enough to fix that change, should it prove necessary. She was the first to make her change this far back in the timeline.
She wondered what it would bring, later on.