Basic Trope: A person who falls in love, prompting a Face–Heel Turn.
- Straight: Bob falls in love with Alice. However, due to Sanity Slippage, Bob becomes a Yandere.
- Exaggerated: Bob becomes an Omnicidal Maniac as a result of having a slight crush on Alice.
- Downplayed: Bob falls in love with Alice, thus becoming a cold Jerkass to drive others away from her.
- Justified:
- Bob has Blue-and-Orange Morality. He doesn't even know good and evil and he thinks this is completely normal behavior.
- Bob has some sort of personality disorder, this is his "love language".
- Bob and Alice live in a Crapsack World, his behavior is due to him becoming a Well-Intentioned Extremist or Knight Templar.
- Inverted:
- Bob is a villain, but falling in love with Alice prompts a Heel–Face Turn.
- Bob was always a villain. He just happened to have fallen for Alice.
- Bob's apathy and/or resentment towards his friends and family allow him to act for the greater good, once they become obstacles or are taken hostage by the villain.
- Alice, Keeper of Hearts has become a smothering, controlling figure thanks to Bob's vile schemes (You Make Love Evil?).
- Subverted: Bob was never really in love with Alice, he just used her as a pedestal so he can commit all sorts of atrocities.
- Double Subverted: ...At least that's what he wants people to think.
- Parodied: Mere seconds after falling in love with Alice, Bob turns into a Dastardly Whiplash Card-Carrying Villain who steals candy from babies and jaywalks "for" Alice.
- Zig Zagged: Bob is in love with Alice...but not anymore. But wait, he fell in love with Veronica. Hold on, Veronica's a lesbian, so he falls back in love with Alice.
- Averted: Bob does not become evil due to falling in love with Alice.
- Enforced: ???
- Lampshaded: "For my love, I will do anything. Anything."
- Invoked: Alice is a vamp. She's trying to make Bob evil.
- Exploited: Alice uses Bob's newfound bloodlust for her for her own personal gain.
- Defied: As hard as it is for him, Bob never lets his emotions get in the way of what's right.
- Discussed: "Bob! You can't do this! Being in love is not an excuse for these heinous crimes!"
- Conversed: "Wow. Bob's Face–Heel Turn was prompted by being in love. How original."
