The corruption energy monsters didn't just let Morak and the rock creatures escape that easily.
When the rock ball covered in light started ascending to the sky, the corruption energy that was on the ground also started surging.
The corruption energy monsters started gathering together before going up into the sky as if they were chasing after the glowing rock ball. It didn't seem like there was a problem for them to reach up into the sky, no matter how high up the glowing rock ball went.
It would never run out of corruption energy to keep building these tentacles that were chasing down the glowing rock ball.
So in the end, there were parts of the glowing rock ball that had to be discarded.
It wasn't that they were being discarded to reduce the weight, they were being used as a sort of bait for the corruption energy tentacles chasing after them. The corruption energy tentacles were reacting to the parts of the glowing rock ball that were being released.
