- They do bad things because they’re scared.
- They’re gullible or misinformed. Example: somebody who has been told the heroes are out to hurt them.
- They are desperate for interaction, validation, kindness, or attention, and the dark side gives them those things.
- They want to change their allegiance, but are pressured by people close to them to stay evil.
- They have an otherwise noble goal that they will do literally anything to achieve. Example: somebody who wants to protect their child, even if it means throwing other children into danger.
That last one…my favourite…