One of the best Star Wars video game characters ever is now canon - again.
The Star Wars: The Rise of Skywalker: The Visual Dictionary book references Revan from BioWare's wonderful 2003 Star Wars: Knights of the Old Republic game, making the popular playable protagonist canon again after Lucasfilm wiped the extended universe slate clean back in 2014.
The book has a page on the Sith Troopers, which are organised into legions each named after "an ancient Sith lord". The third notable Sith Trooper legion is called Revan Legion, which makes Revan from KOTOR canon.