Prior to release, Justice League United was originally going to be the latest volume of Justice League of America retitled "Justice League of Canada" following the events of Forever Evil, and as such, creator Jeff Lemire wanted to create a new character that represented the native people of Canada, his home country. In order to make sure he depicted Cree culture faithfully and with respect, Lemire took many trips to the Cree community of Moose Factory where he'd teach art classes to many of the children, while getting their input on what they'd like to see in a superhero who represented their culture. In the end, both Equinox's appearance and seasonal power set were heavily influenced by what Lemire learned from the Cree people in Moose Factory.
Major Story Lines
Justice League Canada
They introduce Miiyahbin Marten leaving her school with her friend in Moose factory Island, her friend was trying to talk to her however she was very distracted and decided to go straight home like her granny asked. When she got home there was someone waiting for her asking for her help. Telling her that it was too late, that the Whitago is here, telling her to say the word as he transforms into some kind of beast, she then yells "KEEWAHTIN" and transforms blasting him with some sort of energy, he then transforms to look like her telling her that she can't run from herself, it then appeared as it was all a vision and her granny came to comfort her.
Miiyahbin and her friend Heather discover the base and explain that it was part of an old NATO radar base from the 80's, there they are attacked by the creature she saw before, flying, propelled by smoke, and takes Miiyahbin. Miiyahbin wakes up frozen into the wall of a cave and an old man wakes her up calling her granddaughter. Miiyahbin is confused as he isn't her granddad, and asks who he is, to which he answers, he is one of "The Seven". Miiyahbin hears the Whitago coming back and begs for help, he tells her only she can save herself with a word. The man explains that the seven live within all "our" people, but she is special, because within her also lives the beast, the Whitago.
Alanna Strange finds herself in the Bunker after being Zeta beamed from Rann, and puts on a suit that is just like Adam Strange's after hearing nearby sounds, and finds Miiyahbin's friend Heather and agrees to help find her. While following tracks outside they encounter the Whitago and Alannas blaster is able to deter it, however it keeps returning, so they hurry and are able to find the cave Miiyahbin is trapped in. They find Miiyahbin and offer to try and melt the ice, but she is just scared of what will happen when she says the word, as she knows only she can stop the Whitago, but as it approaches she knows she has to say it and is able to stop the Whitago with a single blast, shortly before passing out. Alanna Is able to carry Miiyahbin back to the bunker just after the members of Justice League United return and decide on a name. Miiyahbin discovers that her grandmother was her predecessor as Equinox and that her long lost father was ultimately the Whitago. Through this, she accepts her powers and place in Justice League United by freeing her father.