[Klashikari]

Let's see... these are only my interpretations because I obviously didn't catch everything:

Spoiler for identity of new characters. Mild spoilers:

Eva-Beatrice: in Episode 3, Eva revealed that her past was in huge turmoil because of the inheritance issue with Krauss.
There isn't much hint if it is a split persona or whatnot, but there is a "witch" within Eva, and both are "Ushiromiya Eva", though the Rena like one with the seifuku pretends that she has magic and as long as Eva believes in it, the magic will goes on.
After a little while, Eva was able to find the Gold. She was really in ecstasy, but in the shadows, the witch didn't want to share the gold with any of the other siblings, and Beato pays her a visit. Since she resolved the riddle, she gets the right to take the place of the head of the Ushiromiya family, and becomes the new "Golden Witch, Beatrice". Hence she became Eva-Beatrice.

Beato is guiding her "apprentice" a bit, but it is quickly revealed that Eva-Beatrice is as psycho or even more than beato and goes on a rampage, to much Eva's dismay.

Ronove: he is serving beatrice because of a contract, though he seems to share a special bound with Beatrice. Ronove is actually difficult to gauge as he seems in favor for Battler as well.
He is acting as Beato's proxy times to times and seems to enjoys the antics between beato and Battler.
Once Witch Eva became the new Beatrice, Ronove the serves her, but still stay on good terms with Battler and Beato.

Siestas: these are the bunny girls that Eva-Beatrice summoned when the sisters of purgatory failed in their mission to eliminate some characters. These have an absolute weapon that is activated once the target's whereabouts and identity are confirmed (this can be done from AFAR). The weapon is a golden "snake" that will chase the prey wherever it is without fail, piercing their vital point. Witches cannot avoid this either. This weapon can also be used as a way to fish out the corpses and retrieve them for the siesta.

Walgiria: Beato's mentor. Walgiria is the "previous beatrice, the endless witch". She is extremely composed and gentle, who has a very different mindset than Beato: the endless magic isn't supposed to be used for such destruction etc.
She will assist Battler in the "in game tea parties" against Beato then Eva-beatrice, but in the end there is some plot twist...

It is kinda digest, and I don't think I put all the details, but heh.