>>55193468none of grimsley's pokemon are particularly evil even in their dex entries. You could argue sharpedo, but it's mostly called a bully.
Now Iris on the other hand has a Hydreigon that doesn't need to run frustration. But she's also a pure of heart character.
hydreigon is one of the few pokemon that is described as expressly evil, even more than something like gyarados, but the latest Violet entry says the following
>It's said that Hydreigon grew ferocious because people in times long past loathed it, considering it to be evil incarnate and attacking it relentlessly.So who knows. You're probably right that it's just a misunderstood Pokemon in a toxic relationship with its trainer, and can be a perfectly nice pokemon if raised well.