Is yourself a irregular plural noun?

The Word 'yourself' is not a noun; the Word yourself is a reflexive pronoun, a Word that takes the place of a noun that 'reflects' back to the noun antecedent. Example:

Dad made himself some breakfast.

The reflexive pronouns are also intensive pronouns, Words that emphasize the noun antecedent. Example:

Dad himself made breakfast.

The reflexive/intensive pronouns are: myself, yourself, himself, herself, itself, ourselves, yourselves, themselves.