Havok’s reeeeeeally worried about what Hiss could do in the future more than anything. Kaos is too proud of her to see any dangers, and Feur is as well, but Havok’s fully aware of her morals. Or, lack thereof.
She’s threatened him many times, usually it’s over small squabbles like teleporting him to different places of the castle. While it comes off as playful to others, Havok knows why she does that; to remind him that she could easily teleport him to the base of the city where the poltergeists can get him, or worse. She hasn’t, but it’s her way of saying ‘stay out of my way, or I could easily do away with you and nobody would know’. Havok has the upper hand for now, knowing more about Kurosian magic, and often does the ‘reminding’ her that he’s stronger and smarter than her, for now. He’s stubborn in his own way and refuses to let her subdue him, but he knows the danger she could pose when she gets even older.
Viril and Luminous are aware because Havok’s told them. Luminous wont admit it, but he’s veeeeery afraid of Hysteria and often urges Havok to kill her first. Hysteria doesn’t like Luminous either, since he’s a Light elemental, something she’s very weak against.
As for Voteil, he won’t go near Hysteria. He can see glimpses into the future, this dimension and anothers, and it utterly terrifies him. It reminds him a lot of The Fall, of Malefor. Havok’s unaware, but Voteil will enter his dreams and implant the visions he sees of Hysteria to warn him of some things that could be dangerous, but Voteil hasn’t honed his abilities, so he often blurs which future is the current dimension’s future. Big Bro Vovo tries 8,D
~Weird Hyenas
