Just because a phenomenon is emergent doesn't mean that it is not objectively real. "Evil" is emergent within living systems, and more concretely, among human create social systems (and only those so far as we know). We can think of a lion rending apart an antelope as "evil" in in the sense that it is the darker side of life, but not really in the sense that it is wrong. Certain human behaviors we can say are evil, and the motivations, forces that incentivize those behaviors, social systems that reinforce them we can call evil as well.

So yes, evil does exist.