Hi!
I think I had a similar problem. My king fell down and the platform is on the bottom too and I couldn't see him as well to bring him back up to open up the door.
What I did was basically get my screen to a point where I could see the king at the bottom. So I made Toku stand where the ice was or under the cliff and a little bit away from the locked crystal door. From there, you can kind of see the bottom, but it's not low enough to see the king. So I made a cyclone and drill down to kind of move the screen lower to see the king. It kind of took a while experimenting with the cyclone and drilling, but eventually the screen moved low enough and I was able to see the king on the bottom left hand corner and I made him sing and got the platform to rise.
I hope that made sense! Good luck!