Behza Rianu was an unjoined female Trill serving in the Trill Defense Ministry's Defense Command in the 24th century. She had purplish spots and a quick temper.
Rianu was widely thought to be one of Defense Command's best officers. She also had political aspirations with ambitions to be a senator in the Trill Senate. However, it was suspected that her temper prevented her from achieving that goal.
During the neo-Purist instigated riots and bombings on Trill in early-October 2376, Colonel Rianu was in command of Leran Manev's security command centre below the Senate Tower. When General Taulin Cyl, Hiziki Gard, Ezri Dax and Julian Bashir arrived, Rianu briefed them of the planet-wide status. She also made her opinion clear that Gard should not be present in the command centre due to his notoriety, but she was overrided by Cyl. (DS9 - Worlds of DS9 novel: Trill: Unjoined)