Improving Caesar Cipher security One of the weaknesses of Ceasar is that an attacker knows the order of my alphabet, IE ABC...Z

If I scramble this, then are there enough permutations to ensure my resultant ciphertext cannot be brute forced.
Does this then only leave me vulnerable to frequency analysis.
This is a monoalphabetic substitution cipher (with a mixed alphabet; in the first section of the article there is a paragraph about its security)

While the keyspace of this cipher is huge (relatively speaking for a classical cipher) with $26!\approx 2^{88.4}$ possible keys, it is still quite easy to break with frequency analysis.

Caesar is much worse of course, because you can simply try out all $26$ possible keys, and that is not possible for a simple substitution cipher (with arbitrary permutation).


  Does this then only leave me vulnerable to frequency analysis.


Well, that statement is true. But "more than almost nothing" doesn't mean much.