You have become a rival!

From Season 5 of Star Wars: The Clone Wars.

After seizing control of Mandalore and taking over Death Watch by killing their leader Pre Vizsla, Darth Maul uses the Duchess Satine as bait to lure Obi-Wan Kenobi into a trap.

Obi-Wan tries to rescue the Duchess, but fails, and Maul takes both of them back to the palace.

There, with Obi-Wan on his knees, Maul kills Satine in front of him.

Across the galaxy on Coruscant, Darth Sidious feels a disturbance in the Force, and immediately travels to Mandalore to dispose of his former apprentice personally.