These concept art designs are from Joseph Kahn, who collaborated with Ironklad Studios, and are not an example of del Toro’s version, as The Shape of Water director pointed out on Twitter.
The most heavily associated name with Justice League Dark is Guillermo del Toro, who was originally attached to bring the movie to the big screen.
However, del Toro eventually left the project and Doug Liman took over.
The pieces of concept art also envision the actors who could have been good fits for the characters.