In Elba's own words:
"… Nic Cage came back one day on set … and he looked a little bit tired, a little bit – kind of like he'd been up all night. So I was like, 'Hey Nic, man, how you doing, man?' and he said 'I'm alright,' and I said, 'You seem a little spooked out,' and he said, 'Yeah man, I went up to Dracula's castle … the ruins up in the mountains, and I stayed the night,' and I said 'What?! Why?' and he said, 'I just had to channel the energy, and it was pretty spooky up there.'"
"We were shooting in Romania, Transylvania, and he just went up there to spend the night, as you do. And then he walked away. True story."
So, is Nic Cage really a vampire? The truth is out there.