The Sapient Council

Aristocratic Totalitarianism

Totalitarian

Many of the greater races are quietly unsure of who is more supreme over who. There is a silent "gentleman's" agreement between Greater Races to not invade or provoke each other's territories. Each contributes to the Council, while secretly trying to figure out who is Greater.

Technology and Psy

Greater races use a mix of Precursor artifacts and psychic abilities to control their general populations.

Class structure wherein older, psychic races are above younger, non-psychic races

Fascism

While individual planets are differ, the galactic consensus is that not even your thoughts are to be kept from the Council. Mindwalking species are employed to that effect.

If a race can prove its sentients, the Council will allow it to become subservient. This process usually costs the entering race lots of resources and individuals as they are used to bulk up the Council where ever it is needed.

Obedience to the Hierarchy
All creatures must be registered with the Council. Psy creatures are put in a specific registry.
Psy creatures must serve mandatory time in the military.
Drugs: Planet-specific
Techiism: Yes
Minor crimes: Penal colony or conscription
Major Crimes: Penal Colony or Mole-Guillotine

Anything that can be a resource to the Council will be used.
Planets are strip-mined, cracked, or over-colonized to the benefit of the Council.

Clerical Fascism

"Clerics" in this case being the psychic creatures.

On a racial scale, there is no election. Species' statuses are decided based on their average psychic ability. Government positions are generally awarded through meritocracy, though each race has its own way of deciding it's representatives.

The Sapient Council is at war with the Union of Humanity.

All other galactic entities are in a cold war with the Sapient Council.

Eons before humanity, psychic sapients formed the council as a way of communal reliance. It morphed into the massive government it is today as more and more races, both psychic and not, joined for the economic and diplomatic advantages.

When the Lesser Races requested a banner, this was designed as the most asthetically pleasing to all species.