Cognus was the Iktotchi apprentice of Darth Zannah. She took on Darth Millenial as her apprentice before she'd even killed Zannah, but he abandoned the Rule Of Two and struck out on his own. Cognus then took Darth Staaabb as her apprentice. When Staaabb was killed, she took on Darth Fascist as yet another apprentice. Fascist also abandoned the Rule Of Two and started his own little Sith Gang.
Almost 70 years old at that point, Cognus kidnapped a baby while wandering the swap meet in the Merchant District of Monkeyfight. She named this baby Gape, and raised him to believe in the Rule of Two damnit! She died 22 years later, leaving Gape to finally fend for himself and become a Sith Lord. Bane's legacy continued.