my guardian is a devil

For a good 'A Devil's Guardian' fanfic, the world-building has to be immersive and consistent with the source material. Also, the writing style should be compelling and capture the tone of the original work. Good character interactions and unexpected twists can make it even better.

One idea could be exploring the backstory of the devil's guardian. Maybe they were once a normal being who made a deal with a powerful entity to become a guardian. This could involve their past life, family, and the events that led them to this role.

The fanfic usually involves Zack Fair taking on the role of a protector against evil forces, with lots of action and adventure.

😋I recommend the following novels to you: The Devil's Tenderness and The Devil's Wife: Sweetheart, Please Stand Still. " The Devil's Tenderness " was a modern romance novel about urban life. The male protagonist was an angel in white who saved the dying and healed the wounded. At the same time, he was also the chief CEO of the company. He seemed perfect, but he was actually a heartless, loveless, and heartless devil. There was a battle of wits, courage, and emotions between the female lead and him. " The Devil Dotes on His Wife: Little Sweetheart, Please Stand Still " was a modern romance novel. The male protagonist was a domineering CEO who was high above the masses. He was domineering towards the female protagonist, but in fact, there was a little sweetheart hidden in her heart. I hope you like my recommendation.😗

I'm not sure which novel or movie you're referring to when you say 'the devil is by my side'. Please provide more information so that I can answer your question more accurately.

I'm a fan of web novels, and I don't have any knowledge about the Devil's Side storyline. If you have any more information about the novel, I will try my best to help you.

The popularity might be due to Zack Fair's popularity in the original work. Fans love to see different takes on his character, like being a devil's guardian.

A complex backstory is key. Maybe the character was once betrayed by someone they trusted deeply, and this has made them cynical yet also more determined to protect. This backstory can influence their actions and decisions throughout the fanfic.

It could be an old demigod who has retired from active quests but still has a lot of knowledge and power. Maybe someone like Clarisse's older relative who has seen a lot in the demigod world and is now tasked with looking after Percy.

There's also 'The Devil's Bargain for Zack Fair'. In this fanfic, it shows Zack's struggle between his good nature and the devil - like influence in a very engaging way. It has detailed descriptions of his inner turmoil.