When the hero disarms Kent, Kent throws a tantrum and acts as if the hero confiscated a toy he was playing with.
Zig Zagged: Kent acts like a adult sometimes, and like a child at other times, depending on his mood.
Averted: Kent acts his age.
Lampshaded: "...Is it just me, or does Kent seem like a disturbed preteen wearing an adult suit?"
Invoked: Kent become a villain because knowing they can freely do kids stuff.
Kent pretends to be a Man Child to scare the hero.
The hero defeats Kent with income taxes and broccoli.
Defied: Kent considers childish behaviour immature and unfitting for someone of his age, and is careful to act like an adult at all times.
Discussed: "Doesn't Kent seem really immature for an evil mastermind?"
Conversed: "How come so many of these villains have the maturity of a preteen?"
Deconstructed: Kent's immaturity is a psychological shield-he's knows fully well that what he does is wrong, and takes no pleasure in it. Over time, his emotional growth regressed to a state of Ambiguous Innocence, allowing him to avoid the moral implications of what he does. When he was forced to confront the fallout, his mind broke, and he convinced himself he was "playing" with his targets, with a side of Black and White Insanity (a child's view on morality).
Reconstructed: This doesn't help in the slightest, as he now views himself through that lens, and he eventually collapses into a suicidal depression, which the heroes help him out of. He preforms a Heel-Face Turn and becomes a much happier person thanks to effectively "re"-maturing.
Played For Laughs: Kent's childishness makes him a completely ridiculous and ineffective villain.