Valkyrie Drive: Siren - Breakout

So first, let me get this straight to you guys, the main reason I started reading this is for the Ecchi, now with that out of the way let's start my review for the Valkyrie Drive: Siren. Before reading this, I'm already familiar with all the Valkyrie Drive series, so you might say that my score and review are biased because I like the series, but I'll try not being biased about it. Story: It really surprised me, the Valkyrie Drive series titles that I've seen up to this points are the Valkyrie Drive: Mermaid Anime with Specials & Valkyrie Drive: Bhikkunism manga, I'm also familiar withthe PS vita game Valkyrie Drive: Bhikkuni & I know that there used to be a game with the same name as this manga, so I'm quite familiar with how their story works, but men this manga surprised me, it has the most formulas that are overused throughout the years, where at the start, they're just not that strong, then some drama, then character development, then power up, then some filler and finally the main plot, the main reason it surprised me is that the author manages to fit all of those formula in only a few chapters without it being sloppy or trash, it's like the formula of what most 12 episode anime do, just in manga and done with only 10 chapters. Art: Now this is really something what I love in the manga, at the start, the art style is on the so-so category for me, but after some chapters, the artsyle gradually becomes good and so very erotic that I can't get enough of it, I also like the mangaka's tactic where he/she draws a areolae slip just to tease us, I know that he/she wouldn't draw full nipples because that's what I saw on Valkyrie Drive: Bhikkunism, even though it is created by different artist, I think it's a rule when creating a Valkyrie Drive series title in manga form that they are not allowed to show nipples, I don't know, I just assumed it because out of the 3 Valkyrie Drive mangas, two of them didn't show but only tease it. Character: For character, this one has a better characters compared to Bhikkunism, and since there is a little bit of drama, the characters personality will shine brighter. Would I recommend it? If you're looking for deep, engaging story, NO, if you want just something to read, or a casual reader, or want to bust a nut, YES.