>Dracula gets some his power from outside forces, yes, but it's never been the Devil or other similar figure of evil.
Chaos is Canon Castlevania's Devil figure. It was created from humanity's darkness and will always be around as long as there are humans.
>The closest there's been to a single entity responsible for his power was the castle's heart of chaos Soma beat in AoS, and, even after it and the castle were destroyed, Soma still retained significant power just by being Dracula's incarnate, no outside forces necessary.
Chaos cannot be destroyed, not for good, as long as there are humans. And Soma never achieves his full might unless he becomes the Dark Lord.
>It's hard to blame his actions on outside influences or his own vampirism when, before he ever became a vampire or ruled over darkness, he plotted to have his best friend's fiance kidnapped by a vampire so she would be sacrificed to make a whip that said best friend would use to kill said vampire, so all he could become a vampire himself just to flip the bird to God.
It's shown in the Canon Castlevania that vampirism warps you. Lecarde's daughters for one. Dracula being treacherous and scheming before doesn't mean becoming a vampire had no effect on him. And that's all relevant since the show treats vampires as just "better" humans.