What is the Island realy, why Flocke cannot pass water and where Desmond comes in all that by unxIII

We were told by Jacob that island is cork, and that cork prevents evil from coming out. That is not fuly true. Evil is energy beneth the Island. That energy was primary reason why Dharma Initiative come to the Island and is was studied by theme till they were killed in the Purge...

Smoke Monster or Flocke cannot pass water because that energy is only under Island. You think that his intantions are to leave the Island whith a plane, that is not fully true. He first muste kill chandidates. How is he going to do that is dont know but when he kills them he will become mortal and free of chains that Jacob put him when he did something very evil, and then he could leave the Island whitouth beeing connected to that energy under the Island which turned him into the Smoke Monster.

So Flocke cannot only pass water, he cannot pass places whithout pocket of energy like one on main and Hydra Island.
There comes Desmod, the only one that survive electromagnetic catastrophe. He is special, rules do not aplay on him, so he has power, going to past, future and sideways whith his mind. He will be big part in stoping Flocke, like Widmore told him, he will have to make a sacrifice. But what will that be?