You see, I see a lot of Saiyan reader x DxD fanfics where the Saiyan struggles to fight several early on villains from DxD, and they're basically Goku, where their Saiyan insticts aren't there, and it annoys me. It's all cliche. I've seen a few that break the mold, but this is directed towards those cliche stories. Each chapter is a different reason explaining why Saiyans are too OP for anything other than DBZ or Marvel/DC. Because those get insane with character power. Specifically, this is to explain why Saiyans break the DxD universe. If you try to do a Saiyan reader story crossover, please take this into consideration.

1: Saiyans are naturally stronger than humans. The babies are as powerful as most human adults. Devils are substantially stronger than humans, but they can't compare to Saiyans.

2: The Super Saiyan transformation is a 50x boost. If a Saiyan character is half as strong as I don't know, let's say Riser. The Saiyan will instantly start bodying Riser and several other characters once they transform.

3: We don't know the exact power difference between higher ranked Angels/Devils/Fallen Angels, making it nearly impossible to tell exactly how much stronger a 4 winged is than a 2 winged and so on.

4: Saiyans have literally unlimited potential. Thanks to the Zenkai boost, a Saiyan can gain an insane power boost after getting gravely injured.

5: I'm not sure that there's an official power scale for Highschool DxD, making it hard to decide who's exactly how powerful.

6: Saiyans can easily get up to Planet Buster level.

Need I go on?