Not finding any good description yet, allow me to add one - actually its very simple: Note: - this works for any NPC that enters conversation with you! -> Using it with Sylgia long term and its working flawless
You can have any NPC as your favorite follower using console. Depending on who you highjack, you may have to set their aggression and confidence up a couple of notches so. Bring up the console, click on the NPC in question and use these commands: trelationshiprank player 4 setrelationshiprank player 4 addfac 5c84d 1 Talk to them afterwards and look for the follow me dialog option.
Credit goes to StormSinger over at Che : Try this.
