I'll say it, and I don't care what anyone else thinks: Nino will always be my favorite girl in the series.
I love her dark pink hair-blue eyes-pale skin combo, it's a gorgeous aesthetic that can't really be replicated well in real life, making it extra exotic. I love her large breasts, shapely legs, and perky ass (it's shown in a few manga panels , and some episodes, so I don't wanna hear any arguments).
I love her thigh high socks which are a great tease without being overly fan-servicey. Along with her short skirt, her lower half is pure sex. Her getting short hair makes her even better.
I also love her fiery attitude. She's got spunk without forsaking her femininity. I'm not a huge fan of overly lovey-dovey soft women. It's not necessarily a bad thing just not my favorite thing. Nino being so fiery and stubborn also lends to one of my strongest fantasies- that of fighting a girl who's got a lot of attitude, overpowering her, and then fucking her while she goes from being a loudmouth to suddenly very submissive. The thought of reigning her in with my dick after a particularly heated exchange or a challenge gets me rock hard.
So yeah, I'm aware Negi wrote her into a colossal bitch and kind of butchers her character, but he pretty much did that with every quint. I'm aware of her faults but chose to focus on the things I like the most, her looks, her personality (without the shittier aspect associated with early Fuutaroy), and what could have been when it comes to her skills and gifts.