mrcrypt's steganography challenge - sphinx

PART ONE

artificial intelligence generated image of what you could call a space sphinx. its body is buried in the sand so that only its shoulders and head stick out of an alien landscape of deep canyons. a small humanoid person stands dwarfed by the sphinx. a caption below the image reads: solve my RIDDLE to win my prize. the word 'riddle' is in all caps.

there are no hints, but this uses steghide.
using "RIDDLE" as the steghide password produces an AI image of a lock.

PART TWO

grayscale artificial intelligence generated image of a lock kind of mounted to the background. there is a lot of scrollwork in what looks like metal. the clasp of the lock fits strangely through part of the background. everything kind of looks like brushed metal, too.

forensic tools like binwalk and foremost will reveal this to be a polyglot file, as well as separate the appended ZIP file.

within the zip file are: 10 image files and a text file.

screenshot of the icons for each of the eleven files.

this is a double-jumble of letters; the red and blue letters in the images, as well as the file names.
said file names are the ascii hex codes for the phrase "offset = 7" (including the spaces).

arrange the red and blue letters in the order of that phrase.

the riddle

surfer near shore
blue wave rides toward
where out again yearns
and passion burns
waves in line
named in time
ridden in sequence
universal secrets

(riddles suck, btw)

this is supposed to be a hint to use doppler shift to determine the shift
of each letter: blue is minus 7 and red is plus 7.
the files with the number 2 in parentheses is the second use of each letter.
using a shift cypher with an offset of 7 on the letters reveals
the steghide password for the lock image which produces the flag.