This is essential what came first, the chicken or the egg
Meaning, if Cole had an idea about KOD, was looking for an artist to best tell it through that skills then its no foul. Id say even if Cole saw his work first and it moved or inspired him to make KOD, no foul
However, if he used dudes art and his life story to create KOD he shady.
Also what was paid for? If he didnt have the wherewithal to get a contract with a percentage of merch vs a flat check at the top its on him