Here's why that matters in the Buffyverse:
* Vampire powers: Vampires have superhuman strength, speed, and agility. They can easily overpower humans and even other supernatural beings, including demons.
* Demon weaknesses: Demons often have weaknesses, like sunlight, holy objects, or specific spells. These vulnerabilities don't apply to vampires.
* Spike's chip: While Spike initially had a chip implanted in his brain that prevented him from harming humans, it was eventually removed. This allowed him to fight freely, including against Buffy.
Key Points:
* Spike isn't a demon. He's a vampire, and vampires are powerful enough to fight humans and other supernatural beings.
* The chip prevented Spike from harming humans, but it didn't stop him from attacking other vampires or supernatural creatures.
Therefore, Spike is able to hit Buffy because he's a powerful vampire, and there's no inherent weakness preventing him from fighting her.