4. THEY NEED INVITATION
Vampires cannot enter a house without being invited by the owner of the house. Although this invitation can be granted by the owner even if he has not lived in the house for years, it can also be done through long distance. As explained by Bonnie, the reason behind Vampires unable to enter the owned property is due to a threshold spell. This spell has no loophole. If a vampire is invited then the barrier disappears, or if the owner of the property is killed or dies of natural causes, there is no long barrier.
3. THEY CANNOT OWN ANY PROPERTY
Due to the supernatural protection barrier of invitation, the vampires cannot own any property. Therefore they habit the houses which are owned by any human where they have compelled the human to do their bidding. The only exception is Hope Mikaelson who is the first living hybrid, since she has not technically died yet, she is not a vampire, but has vampire blood in her system. This allows her to own any kind of property and also offers her immunity towards any sort of invitation.
2. THE MOST POWERFUL VAMPIRE BEING
Currently in the TVD Universe, Marcel is the most powerful powerful vampire. As he is the only remaining Upgraded Original Vampire who transformed using the Lucien’s engineered serum. This makes her much powerful than the Originals, he could defeat and even kill them using his bite. A bite of an Upgraded Original comprises of a dangerous strain of werewolf venom.
1. THE SIRELINES
Every vampire has come from the Original Vampires who are the progenitor of the vampire race. Currently, Rebekah and Kol are the only alive Originals. When Kol died on TVD, his sireline died with him, it’s unknown if he turned anyone into a vampire since his return. This leaves us with only Rebekah’s sireline. When Hollow killed Elijah, his sireline died. Davina unlinked the vampires from the sireline of Klaus. Also, it was never mentioned that if Mikael had ever sired any vampires. But knowing his personality and how much he hated vampires, it’s likely he never turned anyone.