Agent23
"Honey!!! Wheres my Supersuit?"
Likely yes as to the knowing Atronarch. I really like the Prisma and D.N dynamic. As for dust being a rival that makes sense he is actually a normal man who was empowered By Boon so i dont know about him being related to D.N or Prisma.They'll be rivals
Prisma is themed around diamonds, not only she's capable of creating them (a bit like criokinesis) and has psychic and poison immunity but she also controls a produces light, usually in the form of deadly rainbows. She's a veteran hero, yes
D. Nightshade is the daughter of the original "Nightshade". Who was Prisma's heroic partner on the old days until prisma killed her (accidentally, of course). Dust could be her little brother, it's perfect since prisma is inmune to D. Nightshade most lethal powers.
D. N. Powers are based on belladonna. She's a mystical telepath (she won't control minds) that can create and control plants but her most lethal power is the use of poisonous purple energy that infects minds with paranoia and delusions while draining the victim's life force
Would Prisma know your rookie hero?
As for Atronarch yeah id imagine she would know him especially if she is a north american hero. Long story short he was a normal guy who was caught in the crossfire of a battle between Dust and his partner Barbados and the Hero known as Wilder. It was on live news casts, Wilder managed to smash Barbados through a bank knocking him out when they hit the vault. But as he recovered Dust caught him from behind and dusted his arm off. As the hero lay bleeding dust started monologuing about how he was helpless to stop him etc. Atronarch (Adam) was there with his girlfriend taking cover. Some shrapnel from the battle hit her and she bled out in his arms. Once she was gone he stopped caring about his safety for a while and approached Dust telling him he was basically a punk. Dust responded by trying to Dust Adam but it didn't work. Adam absorbed the effect and his power woke up. He managed to clock Dust in the jaw with a punch beyond that of an olympic boxer (in power not form.) And dust, not expecting a normal human to be effective and still caught off guard by his power not working was knocked cleanly into unconsciousness. He is one of the public favorites now but is still dealing with his loss, having powers all of the sudden, and unfortunately he has no hidden identity since he made his debut in his civilian clothes.
Thats the gist ill add more detail in his cs but your welcome to use any of that as you see fit. Needless to say dust promptly escaped, many theorize he had help.