Forum:KB:On Darth Nihilus and the Sith Empire

Was the Sith Emperor aware of Darth Nihilus' existence? Surely the disturbance caused by the destruction of Katarr must have been felt on Dromund Kaas...

If Darth Sion and Nihilus had managed to finish the Jedi Purge and kill Meetra Surik, what would the Sith Empire do with the Triumvirate upon finding out that they had already done their work for them?