Supporting female characters are usually underutilized within the DCEU films — always a shame, because the DC Comics women are leading ladies in their own right, and should be more central to the movies’ narratives. Based on behind-the-scenes pictures depicting Amber Heard in costume, it looks like she’ll be a big part of the action, and thankfully Mera, who is also Aquaman’s love interest, will be central to the film’s plot.
For one, Mera will try to “convince [King Nereus, who plays Mera’s father] to join the right side.” We can conclude that if there are warring factions, then as the princess of Atlantis, Mera will more than likely be at the forefront of all the drama between the different sides. She’ll potentially use diplomacy to help sort things out and, later, her own physical skills on land. Mera is a very central character to Aquaman’s story in the comics, and there’s no doubt that she needs to be front and center in the film adaptation as well.