What are the implications of XORing ciphertext with plaintext?
This is not a correct encryption scheme because it cannot be properly decrypted. Consider $E_k$ to be the one-time pad (OTP), the key being all zeroes. Then, for any message, you have: 

$$C = E_{0^{|m|}}(m) \oplus m = (m \oplus 0^{|m|}) \oplus m = m \oplus m = 0^{|m|}$$ 

Or consider encrypting some random string $r$, then you have:

$$C = E_k(r) \oplus r$$

Which is basically the OTP. How would you expect to decrypt that?

The PCBC mode also does not output this construct as part of the ciphertext but feeds it as input to the block cipher encryption XORed with a plaintext block.