Genesis
The new demi-plane is created within one or more transient planes (such as the Astral, Ethereal, or Shadow planes). Once the transient planes are chosen, they cannot be changed. The new Demi-plane will border the transient planes and travel to the demi-plane will be possible through the transient planes.
You are the master of the demi-plane and decide its traits when it is created, including the environment (such as atmosphere, temperature, etc), shape of the terrain, and even physical properties such as gravity. The demi-plane can reflect almost any desire you can visualize, but is limited by the Essences used during the ritual (GM's discretion). For example, if rock and dirt is desired on the plane, then at least one Essence of Earth will be needed during the ritual. If breathable air is desired, then an Essence of Air is required.
Genesis cannot create life on the new plane. However if the demi-plane's environment can sustain life, living things can be brought into the demi-plane and potentially flourish.
The demi-plane is finite in size, but you can spend a Karma at any time while on the plane to increase its diameter by 50 feet. Additionally, you can spend a Karma to add a Bottle of Essence to the Heart of the Plane (an act taking roughly 1 phase), which will allow you to change the nature and environment of the plane accordingly.
The Planar Heart exists at the center of the demi-plane. It cannot usually be stolen or destroyed through mundane means, but it may be possible to steal or destroy it in other ways (GM Discretion). If that happens, the plane collapses and implodes to the severe detriment of anyone still residing on the plane.