Analyzing the two did everything today, not only in battle but in general, which of the two is more cruel? why?

Or

I would say Poison Ivy. She makes people do things against their will and is far more aware off the things she does. Harley Quinn "just" seems to act out of pure insanity and doesn't really know what she does. She just does it for the heck of it, because it is fun or the joker says so. She doesn't seems to be cunning as Poison Ivy.

Harley really does have a mean streak, but she certainly wavers in her sense of evil. She would probably fit in well with the secret six, in that she has some sort of moral code, albeit flexible, and will show heavy remorse for some of her actions. But if things get out of hand, or if she has to, she has no problem getting fatal.

Ivy just has her own agenda and does not care about how much she hurts of manipulates others, and if she lingers on it, it isn't for long. I think this is only worsened by her latest outing with Clayface, which is the first time ever that I found Clayface compelling because of how betrayed he was at Ivy's hands. I blame it on her roots to the plant world, which dehumanizes her a bit. But in the end, Ivy is definitely more cruel.

Poison Ivy by a fair margin. Ivy is actually... MEAN. Harley is lethal and psychotic but not really all that bad.

Ivy goes for makes her victims or targets plant food or she will be ironic like kill someone with a hatchet. She does cruel things since she sees people being cruel with plants.

Harley was with the joker so she had to learn a few tricks. This should be accounted for. She is also a psychologist, so she can mess people up mentally if she goes there. Harley is more effective in interigation