Don't get me wrong, I'm enjoying this game, but it begs the question: why are they even using Serana for this? It's a new place, she didn't keep the outfits and not even the personality. By the end of the first Succulence she was fine going out naked in broad daylight and now she's acting like she's shy and opening the door in her underwear is crazy. I know she gets more corrupted as the game goes on but it's weird that she has this same arc again, it could have just been a new character altogether. Maybe someone else has already pointed that out and it has nothing to do with the new updates specifically but I just had to say it and I didn't want to look through 46 pages of comments to find a comment about that. Only that is bothering me so far.
Looking at it from a meta perspective:
Why is she here? People like Serena and the dev likes Serena and it makes sense to have her in the sequel since she was the central part of the previous game. (If I remember correctly there was supposed to be a male co-protagonist too but not sure if it's still in the plans, I didn't keep up entirely with the development.)
So why is she different? I don't think her personality is too different. Even in previous game Serena liked to preserve the normal part of her life and have fun at the side. She tried to keep everything moderate (but usually failed), even going out naked in daylight she tried to wear sunglasses and everything to hide her identity (or at least pretend she is hiding it). So her trying to have a normal life is not out of character for her, we just haven't seen the crazy part of her life yet. We are getting hints of it though through flashbacks (in recollection room). As we go on things will escalate back to the usual levels. Also I think it is obvious that it's not just about her in this game, the side characters are a little more fleshed out here and those will become much bigger focus as we go on I'm sure, so this arc in the beginning is just to ease us in and introduce the game and characters.
For the powers it's because we need some sort player progression in the game and that's difficult to do if you start at full power like at the end of succulence. It just won't be fun if player has access to all the abilities at the very beginning. So she is de-powered (but not completely) and personally I think it works in how it is implemented as we have traveled through multiple dimensions and are in a new world. And we have the full control over her attire and the lust meter from the start and we don't have to grind to get to that level again so not all progress is reset.