Here it is broken into parts for two narrators:
Narrator #1 (male):
The Master’s world was once a paradise.
They gathered my ancestors from Earth at the dawn of our civilization.
The Masters showed us the secrets of the universe,
and taught us how to bend reality to our will.
As they dwindled, their power faded,
and the gateway home was sealed.
When the last Master died,
their world slowed to a halt.
Forests burned and oceans boiled.
We were able to endure by studying their knowledge.
and the more we learned,
The more we prospered.
On the Nightside forests withered and oceans froze.
Narrator #2 (female):
On Earth, tales of this world had faded into myth.
We developed advanced technology,
and built ships that could cross the stars.
My ancestors stumbled upon this world,
and crashed on the Nightside.
In time, the castaways flourished.
Our city is a warm light in the cold darkness.
The Great Barrier divides Night and Day,
preventing contact between our two Empires.
I haven't named the planet, but I think that I’ve clarified that it’s not Earth, and I can hint at its mythical associations subtextually later.
What do you think?