Following the release of Justice League later this year, the DC Extended Universe will be delving back into the Seven Seas in 2018 for Aquaman. The Jason Momma-Led superhero flick has already had its main cast assembled for a few months now, but with production scheduled to begin soon, a new name has been thrown into the mix. Dolph Lundgren has been added to Aquaman, and much like his days antagonizing Rocky Balboa, he'll be trying to break the main hero.

According to THR, Dolph Lundgren has been cast as King Nereus, ruler of the aquatic kingdom of Xebel, which is where Aquaman's love interest Mera originally hails from. The article notes that Nereus "claims Mera as his own," and is determined to kill Aquaman, who will be standing in his way. Nererus' is the third villain to be announced for the movie, following behind Patrick Wilson's Orm, a.k.a. Ocean Master, and Yahya Abdul-Mateen II's Black Manta. Lungren's other Aquaman costars will include Jason Momoa as the eponymous protagonist, Amber Heard as Mera, Willem Dafoe as Vulko, Nicole Kidman as Queen Atlanna and Temuera Morrison as Thomas Curry.

King Nereus was introduced in Geoff Johns' New 52 Aquaman run as the ruler of Xebel, an extra-dimensional underwater penal colony populated by Atlantean separatists and criminals. Years ago, Nereus sent Mera to infiltrate the Atlantean kingdom to seduce Aquaman and get close enough to him so she could kill him, but Mera ended up actually following in love with the superhero. When Mera returned to Xebel, Nereus assumed she'd gotten the job done and was ready to become his queen, but he was sorely disappointed. Like Mera and the other denizens of Xebel, Nereus is able to control water and manipulate it into many forms, and that's on top of the standard super strength and underwater breathing that every natural underwater dweller in the DC universe has.

Dolph Lundgren is arguably best know for playing Ivan Drago in Rocky IV, but his other appearances include Masters of the Universe, the 1989 Punisher movie, A View to Kill, Universal Soldier and The Expendables series. He's also no stranger to the world of DC Comics, as he's been recurring in Arrow Season 5 as Konstantin Kovar, the main flashback villain. Perhaps it was his performance on the Emerald Archer's TV series impressed Aquaman director James Wan and other DCEU bigwigs so much that they decided to bring him aboard.

Aquaman swims into theaters on December 21, 2018, but before that, you can take a decent dive into the hero's world when Justice League is released on November 17. Let us know what you think of Dolph Lundgren's casting in the comments below.