Some comics have portrayed her as kind, loving, and motherly, while others have portrayed her as an extreme tree hugger much more interested in plants than humans. She's somehow still able to maintain a loving relationship with Harley Quinn, though, so she must have some humanity. How would you write this character? How would you write her relationship with Harley Quinn?

For starters, I'd get rid of the Ivy/Harley garbage. In fact, I'd just get rid of Harley Quinn in general, or at least retire her for several years. She's an awful character that drags down everyone else by association, most of all Joker.

Next, I'd emphasize Ivy's combination of angry eco-terrorist/seductive femme fatale. More grounded "For Nature!" extremism, less "Protect The Green!" s**t. Leave that to Swamp Thing. Her being all motherly, loving and affectionate should be a rare instance, where we see a glimpse of humanity in a mostly cold, ruthless woman. Introduce a complex love/hate relationship with her and Batman, maybe a bit like Batman/Catwoman sometimes, but fifty times more violent and unstable and utterly unhealthy.

Also, retcon Jason Woodrue out of her origin story, bring back Marc LeGrande.

I would write her and Harley as BFFs but thats about it.Her and Swamp Thing would be a duo to protect the green from.any threats (Heroes or Villains).Fighting wise she would be a lot like her Injustice 2 self because she would be Swamp Thing's Green Warrior so she would have some good h2h fighting skills. And for some reason I've always shipped her and Nightwing so they would be a thing.

I think the best thing to do would be writitng her as an ambiguous femme-fatale. Her being just a guardian of the Green kinda contradicts her personality and the nature of her character, in my opinion.

She should be a seductress, someone who clearly has some questionable attitudes but who also constantly teases a good side and shows a lot of sexiness and seduction to make people still like her. She should blurr the line, make readers actually root for her while leaving it clear that she is not to be trusted.

I would make her a clear villain, but I don't think she would be exactly evil. I would try to draw parallels between her and Batman - they both want to protect the innocent and punish those who would take advantage of them, they just disagree on who the innocent are. Ivy might even try to imitate Batman's tactics, adding intimidation to her methods of persuasion, and going as far as to indoctrinate children to take up her cause. She would likely understand Batman's passion and commitment and try get him to see the "true" evildoers, while Batman would likewise try and make her see how extreme her actions are.

And no Harley. She's a fun character sometimes, but I think her relationships with characters often hurt them, especially Ivy. I can see them being friends in Arkham, but ultimately their goals are too different for a partnership to work beyond giving the other a place to hide now and then.

The thing about Ivy is that she's brilliant, she's calculated, she is aware of her strengths and weeknesses and though she's not necessarily a good person she's one of the most redeemable "villains" becuase she's not after world domination, but she's not above crossing lines. She's willing to kill to protect the environment and her ideologies are rather extreme. She's a really complex character so to write her properly one needs to be able to examine all the parts that make up who she is as a person rather then a superhuman.

A beautiful woman

Cares deeply about plants

Still hold compassion towards children

Intellectual

Manipulator

Extremist

Kills on occasion

Scholar

Educated

Determined

With this small list we know a few attributes that make up her character aside any other character involvement, how she communicates with others is a different story. So that's how I'd write her as a strong woman with a powerful will who isn't afraid to kill for her beliefs.

Naked... mutant, or half mutant.

Able to grow plants from her body, to create various weapons and armors/suits with it.

lets say moral terrorist.

No HQ !!!