What will be Elijah’s downfall? Daniel Gillies dove deep into the motivations of his on-screen counterpart, The Originalsmost proper of vampires, Elijah Mikaelson, in a recent video interview with Alloy Entertainment. What did the New Zealand actor say was Elijah’s greatest weakness?

“I think Elijah’s downfall is ... he feels a sense of disgrace, which even the centuries could never wash away. And that he failed his brother in some way and he can’t un-live or forget those experiences,” Daniel said, breaking right through to the central conceit of this series: the twisted relationship between the Mikaelson siblings. In some ways, it seems that Elijah never forgave himself for helping his parents bind Klaus’ (Joseph Morgan) werewolf side all of those years ago. He betrayed his brother first, so — however many times Klaus does the same — Elijah will always keep trying to make up for that first betrayal.

Daniel described Elijah’s dynamic with Klaus as “an abusive relationship,” as an illness that Rebekah (Claire Holt) also suffers from: “I think she suffers the same affliction Elijah does. We just keep demonstrating all this allegiance to this guy who doesn’t seem to reciprocate.”  

Does Daniel believe Klaus will ever change his wayward ways and choose loyalty to his brother and sister over revenge or paranoia? Doesn’t sound like it — at least, not in any consistent way.

“I think [Klaus’ betrayals are] going to be the saga that happens throughout time,” Daniel said. “I think the perpetual sickness of Elijah is one of the cornerstones of the show.” Bummer. We certainly hope Klaus has the potential to change and redeem himself as a brother and person — even after all of these years of unforgivable behavior.

It turns out Klaus isn’t Elijah’s only weakness, however. According to Daniel: “He has two illnesses: One is his devotion to his brother. The other is girls.” Sounds like, even if there isn’t hope for a better fraternal relationship with Klaus moving forward, then there might be for a romantic one with fierce werewolf Hayley (Phoebe Tonkin). We’ll take what we can get!

Do you agree with Daniel’s assessment of his character’s motivations? Do you think Klaus will ever change? Sound off in the comments below!

The Originals returns Tuesday, January 14 at 8 p.m on The CW.

Kayti Burt is a contributing writer for Wetpaint Entertainment with a penchant for all things pop culture. Follow her on Twitter and Google+!