I would make Gregís theme an abbreviated version of Durkonís. If Durkonís theme is in quarter and eighth notes, then Gregís could be whole and half notes, long and sustained, taken from Durkonís theme; or skip multiple notes in Durkonís theme all at once to go on to the next sonorous tone. Greg only knows some of Durkonís life, not the whole thing.
Example Durkon, with numbers instead of notes:
1 2 3 2 3 4 5 4 2 1 5 3 6 5 1
1 ... 3 ... 4 5 4 ... 5 ... 6 5 ...
The Giant says: Yes, I am aware TV Tropes exists as a website. ... No, I have never decided to do something in the comic because it was listed on TV Tropes. I don't use it as a checklist for ideas ... and I have never intentionally referenced it in any way.