The Maelstrom Mod introduces four new races to the Sins of a Solar Empire Rebellion Universe. They are independent of the original races and have unique strengths and weaknesses. Maelstrom is available for Rebellion, Diplomacy, Entrenchment and Original Sins.
New Worlds of Maelstrom
Massive storms rock the surface of this world. So why settle here? Green power - tidal and wind conversion plants can generate huge amounts of energy.
Planetary turbulence and storms are a result of unusual Gravimetric distortions in the gravity well. Orbital satellites can track these distortions and the telemetry used to amplify friendly fire.
What does it mean by tempest?
You could read the description; Tempest is a form of storm, and the description points out that the surface is 'rocked' by storms.