You may learn that Revan and Exile fought. Revan's canon refers to a Jedi male, and Exile's canon refers to a Sith female. Either they had a love interest, and one of them killed the other. One became a Sith Lord, and the other became the apprentice. Or, they both became Jedi, fought against the threat in the Unknown Regions, and then died in the process.
R.I.P. to 'The Source' and 'MacCorp'