In Transformers fanfiction,the concept of Primus being the very core of Earth, acting as its life force and creating the original "Primes" (powerful Transformers leaders) is a common theme, often drawing on the established lore where Primus is a benevolent, planet-creating entity in the Transformers universe.

Key elements of this storyline:

Primus as Earth's core:

The story would depict Primus not just as a deity, but as the very heart of Earth, his energy flowing through the planet and sustaining all life on it.

Creation of the Primes:

When the planet was forming, Primus would be shown to have consciously molded the first Transformers, known as the "Primes," imbuing them with special powers and a deep connection to Earth.

The 13 Primes:

Many fanfictions would focus on the "Thirteen Primes," a group of exceptionally powerful Transformers created by Primus, each with unique abilities and destined to protect the planet.

Possible plot points:

Awakening the Primes:

A story could involve a threat to Earth causing the dormant Primes to awaken from their ancient slumber, their connection to the planet's core allowing them to defend it.

The Matrix of Leadership:

The Matrix, a powerful artifact in Transformers lore, could be depicted as a fragment of Primus's essence, further strengthening the connection between the Primes and Earth.

Conflict with Unicron:

As Primus's evil twin, Unicron could be portrayed as a force attempting to consume Earth, drawing power from its core, and creating a major conflict for the Primes to face.