So I started thinking about people who professionally train other
people, shape their lives and thinking, and make sure they're safe
while doing so.
The "Jeeves" being corrupted got me thinking about how words change and such.

So "Deeaye" pronounced Dee Aye came to mind. Drill Instructor.
So I thought maybe a name based on a famous historical DI... and web searched.
https://en.wikipedia.org/wiki/Drill_instructor

The entry for the Royal Australian Navy caught my eye,and the HMAS
Cerebus entry...
Cerebus has mythical connotations of the guard dog to the afterlife,
and that kinda led to a little twist - your Cerebus is your guard
through childhood to the after (childhood) life.

That also got me skimming wikipedia... https://en.wikipedia.org/wiki/Pursuivant
The part about the Masonic meaning of the term came to mind, and I
pictured the idea of "The one who guards the door (path) to adulthood,
and announces (instructs) concerning what comes through the door"

Skimming through medieval titles, I ended up with
https://en.wikipedia.org/wiki/Oriflamme
The idea of it meaning standard bearer, keeper of honor, etc made
sense, then I scrolled down a bit and saw a banner that if I squinted
a bit I saw the 3I's Sunburst on it.
I had this picture of the guy who stands next to a noble, bearing the
standard for them, and whispering in his ear the correct actions that
wouldn't dishonor the family's name.

Continued skimming found https://en.wikipedia.org/wiki/Groom_of_the_Stool
This kinda made me grin, as what came to mind was "the body guard
that's so close he changed my diapers as a kid"
The added connotation of "Groom" as in "grooming a person for office" fits in.