As we found out last issue, Mera was sent to Atlantis to kill Aquaman. Her home, Xebel, is a sealed off under water world, but she neglected to mention it being a penal colony better known to the world at large as the Bermuda Triangle. The Triangle exists to seal them in, and this would make them the cause of anything bad to ever happen there. Mera was trained from birth to be the ultimate weapon of her people and her father to be used against the Atlanteans. That was who she was, it was her drive and goal and purpose, a living weapon to kill the monarch of Atlantis. When an opening was found, she was released from their prison to carry out the mission.
But then she met Arthur and discovered that nothing she had been taught made sense anymore. This was not the evil vile monarch that she had been raised to kill. So she buried who she was, became his Queen, and found happiness for the first time in her life. Something that lasted until Black Manta killed their son. Which we find out she blames herself for, as Manta met her people long before he crossed paths with Aquaman.
Tags: Brightest Day, DCU, Geoff Johns, Mera, Peter Tomasi, Spoiler Warnings