Factual error: When Blade notices the piece of Dracula's armour in the Nightstalkers' headquarters he's shown an image of what the full armour looks like. It'd be impossible to extrapolate a full suit of armour from such a small piece.
Blade: Trinity (2004)
Plot summary
Directed by: David S. Goyer
Starring: Ryan Reynolds, Wesley Snipes, Jessica Biel, Kris Kristofferson, Parker Posey
After Whistler is killed by the police, Blade joining forces with two vampire hunters, part of a group called the Nightstalkers, as they tackle the powerful and ruthless villain Danica Talos (Posey), her brother Asher (Rennie) and her minion Grimwood (Triple H). After harvesting the superior blood of the ancestor of all modern vampires, Talos has resurrected the man now known as "Drake" (notice the modernization of the Dracula name) from a century-long sleep in the hopes of finally getting world control for all vampires. Blade, along with the Nightstalkers must unleash a virus that will kill all vampires, but only are given one chance to make it work.
More mistakes in Blade: Trinity
Hannibal King: Welcome to the honeycomb hideout.
Blade: How do you bank roll this operation?
Hannibal King: I date a lot of older men.
Trivia: Ryan Reynolds gained 11kg (or roughly 24lbs) of muscle for his role as Hannibal King.
Answer: It's possible that he followed one of them back to the base. This is feasible since they wouldn't be able to tell that he was following them because of his shape-shifting abilities.