When I said "the devil made me do it" I was talking in idioms and expressions. Not literally.
Chaos would be the FIGURATIVE devil that influences Death and Dracula to do their evil deeds on an instinctual level, not giving commands, but simply registering as a need, or gut feeling.
Figurative or not the part I'm not buying is the "devil" part. If you're saying "Chaos itself is the
source of evil things that occur by the hands of humans" then I can understand. However devil to me means innately "evil" or evil by nature, whereas chaos in itself is not evil by nature, is what I'm saying. However chaos applied to humans (who have free will) causes the evil which exists within humans to be either augmented or focused etc.
There's no 'The Devil' (entity or influence) in the original CV universe.
Much as we feel the biological need to eat or sleep, Dracula feels a biological need to kill and induce suffering in man. His long exposure to that corruption has changed his very nature and because he was on the inside looking out, he never really noticed until Alucard forced him to see the monster he'd become.
That's not true. The thing that differentiates Vampire biology and human biology typically is that Vampires can live eternally/ prolonged lives, but they have to feed on humans in order to survive, which also doesn't mean killing them. (Although some of them such as Walter have been shown to, yet Walter is specifically shown to kill for pleasure and as a game. He also fed on Lisa and turned her without killing her).
Mathias doesn't have a biological urge to harm people, it was said by IGA he lived a relatively quiet life, undetected by the Belmont clan - which was around 300-400 or so years. His vengeance upon humanity only started when humans killed Lisa.
Side note: why Castlevania dodges the idea of a proper true devil figure is beyond me as almost every mythology features one. In my personal opinion, Dracula doesn't count in this role; he's strictly an Earthly threat with little to no ability to affect anything outside this plane, which means he may be the Dark LORD, but he's no Dark GOD. Much as he's stylized as the "opposite number to God", he can't actually ever do much to actually defeat the God he opposes. Of course, this is assuming that God in Castlevania A) exists at all, and B) is the Christian one as has been frequently implied -- though the bizarre mix of eastern and western religious themes and imagery throughout the franchise really means I can't rule conclusively in ANY direction here as "God" means different things in European and American cultures vs Japanese culture.
The CV universe seems to dip into the entire pantheon of Gods/ deities while having the singular and Christian God. However, there's no need to assume when it comes to Mathias/ Dracula because he was beside Leon during the Crusades and Leon being a holy knight it's obvious their faith was Christianity.
I don't believe his aim was to defeat God (such as Satan was trying to in LOS), Mathias rejected and defied him by gaining eternal life so that he could continue to curse him for eternity. He achieved this already when he received the Crimson Stone, which is what started his feud with the Belmonts (to his dismay, Leon not choosing to reject God with him despite Sara's fate).
I also believe that chronologically throughout the series from CVIII-1999 inclusive, he does further exact his revenge by harming humans; God's children. However, this only happens after they execute Lisa. Dracula basically has little to no regard for God or humans during this time. (We do know, however, that he still acknowledges God exists when he quotes the book of Matthew in SOTN.)
It seems from what I've seen that Dracula intends to corrupt the Earth and humanity which God created, rather than trying to wage a war with God (like LOS Satan).