I'm not entirely sure specifically what 'ppgz x rrbz fanfiction' is about as it depends on the creativity of the fanfic writers. It could be about creating new adventures, relationships, or scenarios involving the characters from 'ppgz' and 'rrbz'.
There isn't enough information provided to really tell the 'ppgz x rrbz love story'. It could be a story about two characters named ppgz and rrbz. Maybe they met in an interesting place, like a magical forest or a bustling city, and then something special happened between them that led to a love story, but without more details, it's all speculation.
One possible plot could be that the rrbz and ppgz teams are forced to collaborate on a school project. At first, they clash due to their different personalities and ways of doing things. But as they work together, they start to understand and respect each other more, and in the end, they become friends and help each other out in future endeavors.
The obvious main characters could be Blossom from the ppgz and Brick from the rrbz. They are both leaders in their respective groups, so it would be interesting to see how they interact and lead their combined team in a fanfiction.
A great ppgz x rrbz vampire fanfic could be the one that delves deep into the backstories of how the vampire situation came to be. It might show how the normally cheerful and energetic ppgz and the rowdy rrbz have to adapt to this new, darker world. There could be a sub - plot about a particular vampire who has a special connection to one of the characters, which adds a layer of mystery and drama to the whole fanfic.
I'm not sure specifically about 'ppgz x rrbz' love fanfics. You could try searching on some popular fanfic platforms like Archive of Our Own. There might be some creative works there.
One possible concept could be a story where the characters from ppgz and rrbz team up to save their city from a common enemy. They could combine their unique powers and personalities to overcome challenges.
One possible plot could be that the Powerpuff Girls Z (PPGZ) and the Rowdyruff Boys Z (RRBZ) are in a competition in a magical realm. But as they face various challenges, they start to see each other in a new light. For example, Blossom Z might find Butch Z's rough - and - tumble ways endearing when he saves her from a magical trap. However, they still have their pride and it takes a series of events, like a common enemy attacking their city, for them to fully admit their feelings. And in the end, they work together to save the day and start a new relationship.
One common theme is the power struggle. Since the PPGZ and RRBZ have their own powers, adding the vampire element creates a new dynamic in terms of who is more powerful. For example, how would the PPGZ's superpowers fare against the vampiric abilities of the RRBZ or vice versa.
You can try fanfiction - specific websites like FanFiction.net or Archive of Our Own (AO3). They usually have a wide range of fanfics, including those related to ppgz x rrbz vampire themes.