A critic on Ibn Taymiyyah's doubts on the "preserving the Sharia testament"

One of the proofs for the infallibility of the Shia Imams is "preserving the Sharia testament" because Shia argue that the Sharia and acting according to that needs an infallible Imam. Just as the Holy prophet's period. After the Holy prophet (PBH) the infallible Imam will protect from Sharia. The "polymath Helli" just like other great Shia scholars argue with the proof, "preserving the Sharia testament" for infallibility of Shia Imams, writing the book "Menhaj al-Karamah" to explain this issue. Ibn Taymiyyah criticizes this proof, trying to provide an alternative for infallible Imam after the Holy prophet. In this essay by a descriptive – analytic method, it is tried to disproof the Ibn Taymiyyah criticisms in this case.