Another theme might be redemption or growth. Maybe Deku, through his relationship with Bakugo's mom, helps Bakugo to grow and change his attitude towards Deku. It could also show Deku's growth as he navigates a relationship with an older family member of someone he has a complex relationship with already.
I'm not sure about specific 'deku x bakugo mom fanfic' offhand. However, you can try searching on popular fanfiction websites like Archive of Our Own. There you might find various works related to this pairing. Just use the search bar and type in 'deku x bakugo mom' and browse through the results.
Another theme could be growth. Deku is constantly growing as a character. In these fan fictions, his relationship with Bakugo's mom might contribute to his emotional or personal growth. Maybe she offers him advice or support that he doesn't get from other characters. And also, there could be themes of unexpected relationships. It's an unusual pairing, so exploring how such a relationship forms and what it means for the characters involved is likely to be a theme.
Often, they portray him as frustrated. Without his quirk, he loses a big part of what makes him feel superior, so he's likely to be angry at the situation and those who look down on him.
In some fanfictions, Bakugo can become more empathetic. For example, if he experiences a situation where he realizes the pain he's caused Deku over the years. His aggressive nature might soften as he starts to understand Deku better. Deku, on the other hand, could become more assertive. Instead of always being the timid one, he might stand up to Bakugo more firmly in fanfiction scenarios.
I haven't read any 'Deku x Bakugo Mom' fan fictions myself. However, you might want to check out some popular fan fiction forums. There, fans often share and recommend their favorite stories. You can also look for tags related to these characters on the fan fiction platforms to narrow down your search.
One possible analysis could be that their relationship in fanfic often showcases a strong bond of friendship. Bakugo's explosive personality and Kirishima's more stable and friendly nature create an interesting dynamic. Fanfic writers may explore how they support each other during battles or in their daily lives at school. For example, Kirishima might be the one to calm Bakugo down when he gets too riled up, and Bakugo could inspire Kirishima to be more confident in his abilities.