Amazon's Lord Of The Rings: Fan-Casting Every (Possible) Major Role

Though Liv Tyler's shoes will be tough to fill, the steely and attractive actor behind Supergirl's Lena Luthor more than fits the bill. She's no stranger to the fantasy genre after her successful stint on Merlin and the bold brunette isn't afraid to jump into action scenes.

Arwen's role could be magnified in the prequel or possible spin-off series. McGrath's time on Merlin shows she's up for the task. She made Morgana a spirited scene-stealer, willing to overtake Camelot through manipulation. While Arwen may be a kinder maiden than Morgana, she's an active aide to Aragorn and company in the films. She transfers Frodo to safety after eluding the Black Riders. Arwen's dainty in appearance yet gutsy enough to confront the forces threatening her homeland. Morgana and Arwen are keen listeners who aren't afraid to speak up and strike down opponents.

The prequel would profit from examining Arwen's young adulthood in Rivendell. Observing the father and daughter dynamic between Elrond and Arwen from the starting point is an alluring possibility since it's such a crucial relationship in Jackson's films. As Lena Luthor, McGrath's the sympathetic outcast of her villainous clan. Both Arwen and Lena make an effort to guard the defenseless at all costs. Viewers of Supergirl would attest that McGrath imbues Lena with sensitivity and determination in the storylines featuring her overbearing mother. McGrath should prevail in plots that pit Arwen against her royal parent.

McGrath would shine more than usual while playing the princess who bears the name Evenstar.