I LOVE THE WAY YOU DRAW! I've seen all your pictures....(yes..even the ones that aren't in DA......the ones that scratched the surface of my brain.....*shudders*)But you draw like as if you were Ub Iwerks!
I think what twisted is trying to say is that Oz was put into the wasteland and Yen sid was like the guardian of the Wasteland and only he could come and go as he pleased. Oz just wanted to see his family once more.
I always imagined Yen Sid as being more of a caregiver than a foster father. He was first and foremost master of Wasteland and Mickey Mouse, but he would be kinder to both Mickey and Oswald when he had to be.
I once imagined Yen Sid watching over Mickey more closely and being there for him around the time Walt Disney died.