A “Nite-Owl” is headed under the sea.

Aquaman is going to have a serious case of sibling rivalry on his hands.Patrick Wilson has joined the superhero film as Ocean Master, who in the DC comics is the half-brother of Arthur Cury (Aquaman). Known as Orm Curry, he grew up jealous of his half-brother’s powers (he himself had none). Orm eventually turned to super villainy, using technology to transform himself into the Ocean Master.

Director James Wan confirmed the casting news on Twitter Monday. The two have a long history working together on projects such as The Conjuring and Insidious.

The two have worked together on projects such as The Conjuring and Insidious.

Wilson also played Nite Owl in Zack Snyder’s 2009 comic book adaptation Watchmen, and is just the latest alum from the film to join the DC Extended Universe. Billy Crudup is attached to The Flash movie, while Jeffrey Dean Morgan played Bruce Wayne’s father in this year’s Batman v Superman: Dawn of Justice.

Jason Momoa is starring as Aquaman in the DCEU, having made a cameo in BvS and with him set to appear in next year’s Justice League. His own solo adventure film, which also stars Amber Heard as Mera, will hit theaters on Oct. 5, 2018.