Continuity mistake: When Anna and Van Helsing is looking down the well for the bride who is hiding there, notice the width of the well. When we are looking up at Anna and Van Helsing from within the well we can see that the width of the well has increased a few feet. Also Anna's position when looking down the well changes during the shots. (00:27:30)
Continuity mistake: In the scene where Van Helsing is fighting Dracula's brides for the first time, when the sun comes up and they disappear, there is a wooden table behind Anna when she stands up, and there's nothing on it. But a couple of shots later there is the dead body of a man on it.
Continuity mistake: As the cage is being dragged up along the trees, right before Velkan jumps off, you can see ropes and equipment attached to the tree on the right. It cuts to Velkan jumping off the cage and the cage continues being dragged up along the tree. When the cage stops you can see the same ropes and equipment to the right as previously seen. (00:21:05)
Continuity mistake: Right after Anna's brother and the werewolf dive off the cliff you can see Anna getting up a few feet from the edge of the cliff. When it cuts she lies right next to the edge. (00:21:50)
Continuity mistake: When the Bride is down the well in the village, the sun is out. When it goes back behind a cloud, the shadow can be seen crossing the ground. When Carl points this out, the shadow is back where it was a few moments before. (00:27:40)
Continuity mistake: After the vampire has thrown the bull through the building wall we see Van Helsing turning his head around noticing Anna running. If you look behind Anna you can see something orange resembling what could be haystack of some sort. When it cuts to a closer look of Anna running you can still see it behind her. When it cuts back to Van Helsing still looking her direction it is gone. (00:26:10)
Continuity mistake: As the cage with the werewolf in it is being dragged up you see Velkan landing on it on his side. However when it cuts to his loosing his gun he lands on his stomach. (00:21:00)
Continuity mistake: When the Frankenstein Monster manages to get himself loose from the table you can see him ripping off the strap by its attachment on the table. Later when Dracula gets to the table you can see the strap leather has been ripped in two on the middle instead. (00:03:50)
Continuity mistake: When The Velkan saves Anna from the wolf and is subsequently thrown off the cliff by the beast the splash sound as they hit water is heard a split second later. However as the camera pans back we see the cliff is meant to be several hundred feet high. It would be impossible for them to reach the water in that time and the splash sound at that distance would be imperceptible. (00:21:50)
Continuity mistake: When Van Helsing is talking with the undertaker and the undertaker says "Never to late digging graves", he lifts his shovel. When it cuts from behind him the shovel is lowered. (00:44:45)
Continuity mistake: Anna wears high-heeled boots during the movie, but during some action scenes, they are flat-bottomed boots.
Continuity mistake: When Anna and Van Helsing are talking in the castle after the first vampire attack, the weapon Van Helsing is holding shifts from pointing over her shoulder to pointing across his face. (00:38:20)
Continuity mistake: As revealed in the DVD commentary, the character Anna's hair changes somewhat in some scenes. Noticeable is the very slight changes that occur before she finds out her brother is a werewolf. An original mistake was already corrected, but I assure you it's there. It's just hard to see.
Continuity mistake: As Anna investigates the noise at night, her grip on the lantern keeps moving from horizontal in the front shots to vertical in the chase shots. (00:39:45)
Continuity mistake: When we get to Anna, right before she stabs Aleera, we can see traces of the concrete under the snow above her. Two shots later the snow is totally covering the concrete. (01:49:50)
Continuity mistake: After Aleera has grabbed Sara and Van Helsing runs after to the edge of the cliff looking for them, we see him holding his hand to his wound. When it cuts to Carl and the Frankenstein Monster getting to him we see him placing his hand on the wound again. (01:18:05)
Continuity mistake: After Velkan and the Werewolf fall off the cliff, the shot changes to where we can see the area where they hit the water. The ripples are obviously farther to the left from where they should be. (00:22:00)
Continuity mistake: After killing Dr. Frankenstein, Dracula has blood on his lips. After he uses his hand to wipe the blood away, no blood is on his hand.
Continuity mistake: When Dr. Frankenstein asks Dracula "What purpose?", the doctor's hairstyle changes. (00:04:10)
Continuity mistake: When the movie begins and the villagers are raiding the castle, Dr. Frankenstein tries to sneak through a basement door. Dracula produces an explosion and Doc turns his head away. From the opposite angle it's still facing forward.
Answer: After being killed - "murdered" as Dracula stated several times - by Van Helsing, Dracula made a deal with the Devil to regain his life. Carl tells his story when telling Van Helsing and Anna everything that he has learnt.