So this is my character, Nitor, and I just wanted people's opinion's on her before I submit her? I really want to know what I should improve on.

Nitor is kind of a jerk. She's lazy, arrogant, and orders people around, then gets pissed at them when they don't follow her orders EXACTLY. She expects people to treat her like a princess, even if her status as royalty is no longer a thing, and hasn't been a thing since she was very young (presumably, she might have just made it up).
Despite being all this, she's a pretty good fighter, both above and underwater (though she has an advantage in water). She will stab, slice at, or in some way try to make an open wound, then knock down down her opponent and stick her fingers in the wound, which seems weird, but is effective, as she's poisonous. Really, really poisonous.
Seriously, don't let her touch any open wounds, because there's a reason that's her strategy.
She is not especially fast, but she's strong.
She has limited water breathing capabilities, and while her gills can't support her for very long, she can store a lot of oxygen. She is a powerful swimmer and can see well underwater and in the dark, but has somewhat impaired vision above water and in bright light.
Her 'hair' is actually more of a storage space for fat and some air.

No one really knows where she comes from, but she has a lot of money and claims that she is a princess that was stolen from her family at a young age. She just sort of... showed up.

She has a huge weakness for poisonous mushrooms, and will eat them if she can find them. They're most likely what makes her so toxic.

Her intro comic has two pages so far, I'm not sure if I should add more: