Long ago, Antaevum was a part of the Revenant faction fighting in the Skull King's army. However, during the war, Antaevum was sealed away inside of a box by Sanctum forces. This box was buried in the desert that the Crownbreakers inhabit. Long after the war between the Sanctum and Revenant factions was over, the box that had sealed Antaevum was dug up by miners. The seal that kept Antaevum within the box had grown weak with time but still vastly limited their power. Upon discovery, Antaevum's initial reaction was to slaughter every last one of the miners that found them. However, before Antaevum could commit any acts of violence, they had a change of heart. Upon closer inspection, they had actually found these miners to be quite endearing. From then on, Antaevum would in their mind, adopt every last one of the miners and live alongside them as their "grandmother." In return, one of the miners gifted Antaevum a red bow, which Antaevum appreciates very much. Despite the rocky introduction, they're well-liked among the Ribclan. Antaevum carries around a card for identification, along with a pouch to collect any Ceruleum that drips off of them. Prior to being sealed, Antaevum bore a striking resemblance to Charybdis from Greek mythology.
For a quick breakdown of their abilities, they work as follows: Antaevum can create boxes. They can apply whatever properties they want to these boxes, with the only limitations being that the box cannot directly cause physical harm to whatever is INSIDE of it. The box is still allowed to harm whatever is OUTSIDE of it. If Antaevum enters and then exits a box, the box breaks. If Antaevum breaks any of the boxes rules, then the box breaks. Boxes can be solid, but the majority of them that Antaevum makes are intangible AoEs. Antaevum's preferred method of combat is to create a large boxing ring where magic can't be used, and their opponent has to fight them under conventional boxing rules. The boxing ring automatically puts both fighters in the same weight class by adding together their combined weight and splitting that weight in half. Both fighters are provided boxing gloves. They can also inflict claustrophobia on their opponents or provide a feeling of stress by making them feel figuratively boxed in. I might've written too much.