Here's why:
* Noun: A word that names a person, place, thing, or idea. "Minion" refers to a person, typically a loyal follower or subordinate.
* Adjective: A word that describes a noun. There's no adjective form of "minion."
* Pronoun: A word that replaces a noun. "Minion" doesn't replace a noun.
Example:
* The minion followed his master faithfully. (Here, "minion" is the noun)
* The minion's loyalty was unquestionable. (Here, "minion's" is the possessive form of the noun, used as an adjective)