The plot could also involve Red Hood's internal conflict. He might kidnap Nightwing not out of pure malice but because he wants to save Nightwing from something or someone else. Maybe he has discovered a threat to Nightwing that he can't communicate about in a normal way, so he resorts to kidnapping to keep Nightwing safe and explain the situation.
In such a fanfiction, the plot might be centered around Red Hood having some sort of vendetta against Nightwing. Maybe he believes Nightwing has wronged him in the past, and the kidnapping could be a way to get revenge or force Nightwing to face something. For example, Red Hood could be trying to expose a secret that Nightwing has been hiding.
It could be someone manipulating Red Hood. For instance, a powerful crime lord who has some dirt on Red Hood and forces him to kidnap Nightwing. So, in a sense, this crime lord would be the real villain.
In a 'Red Hood kidnaps Tim Drake' fanfiction, it might be about Red Hood trying to prove a point to Batman. He kidnaps Tim as a way to show Batman his methods are wrong. Tim, being the smart detective he is, tries to reason with Red Hood during his captivity and in the end, changes Red Hood's perspective a bit.
Maybe kaldur has been brainwashed. He might be forced to kidnap Nightwing by some evil force. The story could then focus on the other heroes trying to rescue Nightwing and break kaldur's mind control.
His motivation could be related to a difference in ideology. Red Hood has a more brutal approach to crime - fighting compared to Nightwing. He might think that Nightwing's methods are too soft and by kidnapping him, he wants to force Nightwing to see things his way.
One possibility is that Red Hood has some sort of vendetta against Nightwing. Maybe he blames Nightwing for something that happened in the past, like a mission gone wrong that affected someone close to Red Hood. So he kidnaps Nightwing to get revenge or to make him pay in some way.
One great 'Red Hood x Nightwing' fanfiction is 'Shadows and Stars'. It delves deep into their complex relationship, exploring how their different approaches to justice can both clash and complement each other. The story has really well - written action scenes and emotional dialogues that draw you in.
Well, it could be Red Hood himself. Since he's the one doing the kidnapping, he could be seen as the antagonist at the start. But as the story unfolds, there might be a bigger threat lurking in the shadows that makes him and Tim Drake team up.
One possible motive could be revenge. Maybe Nightwing has thwarted Slade's plans in the past, and Slade wants to get back at him. Another could be that Slade sees Nightwing as a valuable asset. He might plan to use Nightwing's skills for his own evil purposes, like forcing him to steal something or gather information for him.
The popularity might come from the complex relationship between Red Hood and Nightwing in the DC Comics lore. Their different personalities and backstories create a lot of potential for interesting character dynamics in fanfiction.
The popularity of 'Red Hood x Nightwing' fanfiction lies in the contrast between the two characters. Red Hood is more of an anti - hero, while Nightwing is the traditional hero. Their differences create a lot of tension and potential for interesting storylines.