Can himself be used as the subject in a sentence?

No, the pronoun 'himself' is a reflexive pronoun used to 'reflect back' to the subject in a sentence.

Example: Dad made himself some breakfast.

The pronoun 'himself' is also a intensive pronoun used to emphasize its noun antecedent.

Example: Dad himself made breakfast.

Even when the pronoun is the first Word in a sentence, it is not the subject of the sentence.

Example: Himself a cook, dad always makes breakfast. (reflexive use of the pronoun, the subject of the sentence is 'dad')