How the MIB will possibly be defeated by Tet9

Based on all of the events this season and where we are currently left, here is how I think that the MIB can be defeated.

Desmond will probably be the guy to stop MIB and allow the others to leave. Richard will probably have to stay back to help. Whidmore said that Desmond would have to do something that Whidmore hopes he will do. I think that those pylons that keep the smoke out will somehow get turned on when hes within them, keeping him trapped, and inside of that circle will be the room where Desmond went through the Catastrophic Electromagnetic Event.(Remember, the pylons were moved from around the plane to around Whidmore's camp) The MIB will somehow be trapped inside of the pylons by, and with Desmond. Richard will hit the switch to turn on the Electromagnetic room once Desmond gets MIB in it. That will be Desmonds sacrifice, Richard stays to die on the island, everyone else gets off on the plane flown by Lupitas. Just a thought, and totally a guess, but if you think about their roles and what the main goal is, I think this works. Their will be no replacement for Jacob, as their is no need since MIB is dead. And thats why we have seen everyone in the flash sideways, if someone were to be left in Jacobs place, then they would not be in the flash sideways. Besides, the very first thing that we saw this season was the island underwater. This tells us that the island is lost forever. I think it makes sense, let me know what everyone thinks.