Blade/Fridge


 * In the first film, Blade is developing a resistance to the serum that suppresses his vampire urges, which seems to imply his vampiric bloodlust is an atavistic leftover of his vampire side. Dr. Jensen develops a serum to remove his vampire side entirely but Blade declines, instead asking Dr. Jensen to make him a new serum but we never see if she can or not. The later films seem to forget about this weakness entirely. But in the 2nd film, he's shown to derive strength from drinking blood and the 3rd film shows him deriving strength from the serum, suggesting its a new serum that provides the same nutrients as blood does for vampires, i.e. working with his urges instead of trying to suppress them. - DarkNemesis
 * And at the end of the third film, Blade seems rattled by the proclamation that "the thirst always wins". So...who knows what the hell is up with the serum.
 * Fridge Logic: Boy... that train going past in the first film as Blade and Quinn fight must have been a mile-long subway train. It's going fast, and still takes forever to pass. Sucker must be longer than any subway station in existence.