Jekyll and Hyde/Playing With

Basic Trope: A character has a good and bad personality in him/her.

Straight: Jason drinks a potion that transforms him into a monster named Johnny.
Exaggerated: Jason is The Cape (trope) who transforms into Johnny, who is a Complete Monster.
Downplayed: Jason is smart but serious, while Johnny is outgoing but emotional.
Justified: There is a stimulant in the potion which drives Jason into an unstoppable rage.
Inverted: Johnny drinks a potion that transforms him into a human named Jason.
Subverted: Jason drinks the potion and finds that the stimulant doesn't effect him.
Double Subverted: ...Until it has totally absorbed into his blood.
Parodied: Upon even smelling the fumes of the potion, Johnny goes on a violent killing rampage.
Played for Laughs: Frank wants to protect Jason from Johnny, the monster. And both hide in odd places where inexplicably Jason disapears, and Johnny appears.