The Senate could advise the Emperor and work on the Eriaduan budget. However, the Emperor could both introduce and veto Senate legislation, and both called and dismissed the Senate to meeting.
Because of the Order of Judges, the Senators, who represented individual worlds and regions within de Borgia's Empire, no longer served or had power as regional governors or representatives in reality.
The Senate could pass amendments to the Articles of Ascension, and apparently had at least nominal oversight of the Eriaduan Military and government bureaucracy.
The day-to-day head of the Senate was President pro tempore. The Senate was, at least in theory, responsible for choosing a new Emperor upon the death or abdication of the current holder of the throne.
The Senate was comprised of at least one representative or senator from each of the Eriaduan Empire's member worlds. The Senators may also represent entire sectors or administrative regions as well, in theory at least.