Board Thread:Manga/@comment-5774380-20160408232143/@comment-26932251-20160410203015

KiruSama wrote: What im scared of is the fact that Reiner survived all that, what im getting at.. Is Zeke and Bertholdt going to be just as hard to kill as Reiner? No, IT'S THE SPINE. Remember what Rod Reiss said, that for a titan to inherit powers from a titan shifter all they really need to do is get the spinal fluid from a human who can turn into a titan.

What this tells us is that the spinal fluid is the key to whatever makes titanization happen and therefore destroying the spine in such a way as to cause the spinal fluid to leak out is the only way to 100% kill a titan shifter.

The mistake that the SC made with Reiner was that they didn't take note of the fact that the Armored Titan wasn't dissolving when Reiner's head exploded and that they should have destroyed more of his body, and specifically the spine, when Reiner was immobile. The thing that annoys me is that they knew about what Rod Reiss said about the spine and they knew that titan serum seemed to have spinal fluid components yet it didn't occur to them to destroy the spine when they had the chance.

Long story short, as long as Bertolt and Zeke are attacked in such a way that their spine is destroyed, they can be killed.