Once you get as high up as you can and can see Cynder circling around glide down to the floating islands to the right. Jump down, past the Jellyfish and then go up the many small platforms ahead. Keep going up this straight path, past the Jellyfish and over many, many gaps. When you get to another Jellyfish, jump on top and then use the platforms directly after it to go to the left and to jump onto the final platform where you can see Cynder.