Another theme is the power dynamic between them. Stolas is a powerful demon with a high social standing, while Blitz is more of an underdog in a way. Fanfictions may play with this power dynamic, sometimes having Blitz gain power or influence in the relationship, or Stolas learning to respect Blitz's agency more. Also, there are often themes of redemption and self - discovery for both characters within the context of their relationship in these fanfictions. They might grow and change as a result of their connection to each other.
A plotline might involve them going on adventures together outside of their usual work - related tasks. They could discover new aspects of each other's personalities and grow closer as a result. Also, there could be a plotline where they face opposition from other characters in the Helluva Boss universe who don't approve of their relationship.
The contrast between their characters. Stolas is refined and powerful, while Blitz is rough around the edges and scrappy. This creates a dynamic that fans find interesting to explore in fanfiction.
You can try websites like Archive of Our Own (AO3). It has a large collection of fanfictions across various fandoms, and there are likely many Stolas x Blitz fanfictions there. Just use the search function on the site.
Magic and the supernatural are often themes as well. Stolas has powerful magic abilities, and fanfics play with how he uses them, discovers new powers, or how his magic affects his relationships. Some fanfics also explore the origin of his magic and how it ties to his family's history.
If Hidan were to be captured and tortured, Kakuzu would be enraged. After rescuing Hidan, Kakuzu would stay by his side during his recovery. He'd be uncharacteristically gentle, making sure Hidan had food and water. Hidan would be touched by this side of Kakuzu that he rarely sees, and it would strengthen their relationship.
One great 'Harry x Sirius Comfort' fanfic is 'A Shoulder to Lean On'. It beautifully portrays Sirius being there for Harry during a tough time at Hogwarts. The author does an amazing job of showing their bond through simple yet powerful interactions.
There's 'Stolas and His Daughter'. This fanfic focuses on Stolas' relationship with his daughter. It shows his more tender side and how he tries to be a good father in the complex world he lives in. It's a heartwarming read.
According to the story, a good listener should show empathy. That means trying to understand the feelings of the speaker. If someone is sad while talking, you can give a sympathetic look or a gentle touch on the arm to show you care. Also, don't interrupt. Let the person finish their thoughts before you start to talk. This gives them the respect they deserve and also helps you to fully understand what they are trying to say.
The story might suggest that respect is a big part of being a good listener. Respect in terms of not cutting in and allowing the speaker to have their say completely. Also, having an open mind is important. Don't judge what the person is saying right away, but listen with an open heart and mind.