I asked a question earlier, how strong is the tree man Lazarus is facing?
Sorry about the wait. Was busy, slept, and went to school. But I'm back and trying to post.
If someone was attempting to level the entire thing to the ground, it would probably take more than their body could handle. The titan is in a way, a living thing and will try to repair/rebuild itself if part of it was destroyed. So I would imagine that someone trying to completely remove a huge chuck from the titan would cause the person to pass out from extreme exhaustion. What I would say is that finding and stopping Gentsai, Taris, or the anima itself (which I will try explaining in the IC). The titan is just a vessel and the anima is the wind and water that will push the the boat to Earth Land.
Hopefully that helps. If not, just tell me and I'll try again.