So Imitation, Swamp Fisher and a Berserker? Not the names I'd pick, but sure. Seriously speaking though, them not being connected to Vena or Vatz is definitely very interesting. Particularly because they have Vena's star motif and portals, but their magic is light colored like Vatz's stuff.
Anyways, my first opinion of each of them:
Imitatio is an arrogant brat who I can't wait to see taking a beating, but has an aura of competence that makes her arrogance feel justified. The quick change of gears the moment Berserga got jealous and the happy and innocent poker face she wears gave her a pretty strong sense of control.
Berserga is kinda terrifying, she SCREAMS emotionally unstable and has the look of someone who's mentally broken enough that she probably tried commiting suicide at least once. In other words, she looks like the type it's impossible to feel safe around because you can't know when she'll snap. Her apparent dependence and clinginess to Imitatio looks about as unhealthy as it gets too, which is likely going to be important.
Pantano Pesca on the other hand I don't really have a good grasp on yet. She has the fangirl thing, but also has a bit of a "holier than thou" attitude, so she reminds me a bit of Sting and Rogue from Fairy Tail, but not quite the same. Not sure what to make of her for now, but my gut tells me I should definitely worry about that fake looking smile of hers, and I really trust my gut, so she has me on guard.