This is tip 3 of 4 for Bubble Witch 2 Saga 83.
Level 83 Cheat #3: Work your way to the middle.
Since this is a rotating cloud, you will need to strategically work all sides. Once you remove the outer bubbles you will be able to focus on freeing the ghost in the center. The most efficient way to do this is to remove all of the bubbles that are touching the ghost. Once you remove the bubbles that touch the ghost, the remainder of the bubbles will fall. Remember you only have 25 moves so make sure that you are constantly scanning the board for any opportunities.