Darth Falsa was never really a Sith. He was a Jedi that had been sent to spy on the Order of Corruption and was taken in by the Dark Side. He later renounced the Dark Side in secret but continued to spy on the Sith and even gave himself the title of Darth Falsa. He was killed by Darth Abusus when he discovered Falsa giving a hologram report to the Jedi Council. He made sure that the Council saw the duel and killed Falsa while they were watching.