Hmmm. Try O MORNING STAR, HOW FAIR AND BRIGHT. (with tune) It cites: I am the Root and the Offspring of David, and the bright Morning Star Revelation 22:16 as its source.

The implication from the Knights' first verse "We are..." rather than "I am" reom Revelations, implies strongly to me that they've not only replaces the Jews as the Chosen ones, but have also replaces Jesus. Worse than I thought.

The phrase "The bright and Morning Star" seems to be used in many hymns but always in praise of Jesus, not of the singer-Knights.