She has an iffy accent, talks too quickly, and is overanimated. Add in to that strange writing (for most of the DMC5 characters) that makes it seem like none of them actually like each other and she becomes pretty unappealing.
Seriously, all most of them do is complain. It’s like the writers couldn’t figure out any way to actually create genuine emotional connections between their characters so they sort of just randomly bark at each other. Nico is the worst offender.
I know the series is known for being cheesy and over-the-top, but I do believe it’s possible to do both.
It has been a really long time since I've actively disliked a character as much as I dislike Nico. I don't really know what it is about her either. Her accent and comedic relief attempts do not do it for me.
I thought I would love her, and be lukewarm on V. Instead I find her accent makes her just tolerable rather than awesome, and V's voice does the exact opposite. He's much more fun than he appears, and has a ton of personality that's really enjoyable.
But I'd buy an alt voice pack for Griffon. Get that Iago out of my DMC!
...Also DMC V is the best game ever made by anyone.