Vika is the fifth prince of Roa Gracia and the guy behind the Sirins and Mariana Model AI—both of which eventually fed into Legion's creation. That made him dangerous enough to earn the military callsign Hveđrungr. He's also the current Amethystus, basically the sole Esper of the Idinarohk bloodline.
He got sent to represent the United Kingdom in the Eighty-Sixth Strike Package, working as an advisor under Vladilena Milizé and commanding the 1st Armored Corps.
Here's the thing about Vika: he's a pragmatist with zero concept of taboo. He'll cross legal, military, and social lines without hesitation if it serves his goals—taking direct command from Lena mid-operation, desecrating corpses to preserve his mother, engineering the Sirins. He doesn't think in terms of good or evil, just what he wants. Shin, who's seen some stuff, described him as an innocent monster—inhumanity that knew no reason. It shook him.
But Vika's got a front he maintains. Publicly, he's just a playful royal kid, one who gets into everyone's business, including the Strike Package's. The thing is, beneath all that, he's not emotionless. He's invested in Lena and Shin's relationship enough to actually chew out Dustin for interrupting them.
Despite not caring about formalities himself, Vika still operates with a kind of noblesse oblige. He only calls people by their last names or nicknames or formal titles, but insists everyone call him by his first name. Even having abandoned his throne claim, he still carries himself like he's ruling over his subordinates.
He's got the reddish-black hair and amethyst eyes typical of an Amethysta. During his first appearance, he wasn't interested in ceremony—showed up to an audience with the King in a regular school uniform instead of the violet-and-black military dress. His official uniform's loaded with medals though.
Content compiled by AnimeList.moe from publicly available sources.