What lies between shadow and light: Hints and solution

[Villane]

Spoiler below!

The Fibonacci series with seeds of 5,6 is
5,6,11,17,28,45,73
but add the digits together of each term (28 -> 2+8 -> 10 -> 1+0 -> 1)
OR use mod 9 but translate 0 to 9

Spoiler below!

Also, if anyone uses software to solve it (i wrote a small Scala program) make sure you use big integers when constructing the Fibonacci series, unless you mod 9 immediately when constructing the sequence. ints and longs aren't enough.

I'm wondering about the other sequence of numbers given in the puzzle: was it a red herring? I didn't find any use for it, both of the keys came from the first sequence.