Background: I've known him for 15 years and have been besties basically since the night we met (so obv we've been planning/dreaming about my wedding since forever).
After the engagement (during a discussion starting to brainstorm ideas), I had casually asked/mentioned I planned for him to be a groomsman (he also knows my fiance well). NOTE! We both come from a theater/dance background with extensive experience being in/running shows and productions
His response was that he didn't need to stand with the wedding party unless I really wanted him to, and that he wants to take on basically being the "stage manager" and helping with the run of show and all the behind the scenes stuff day-of to make sure it's flawless. 
SOOO that leaves me with figuring out how to title his role... We joked about "fairy godmother" (but update to fairy godfather), and that lead to "The Godfather" (as in the Marlon Brando films). I know there are more modern generic terms like "bride's attendant" or "bridesman" other brides have used (and he's kind of a co-Man of Honor with my MOH), but I want to think of a fun title for him that's not TOO out there.
Loved the "Godfather" idea (because he is very much NOT Marlo haha), but for people that don't know him, it might be a little odd. And I'm good with "Fairy Godfather", it'd be generally understood I think, but I feel like there's something better out there I just can't think of right now - SO enlisting the WW community's help!!
ABOUT THE WEDDING: We're a pretty laid-back couple with a great sense of humor and wit. The wedding is semi-formal and we do have a limited amount of famliy, but no one older than our parents and most guests are friends. Still keeping it a little formal/classy, but not afraid to break the mold, especially if we can work in humor 
Any thoughts would be greatly appreciated! THANK YOU! 