An interesting challenge, thank you. My initial thought is that being all-knowing and being all-evil are mutually exclusive, because I define evil not as a force in itself but an absence of good. I go with the analogy that darkness is the absence of light. In practical terms, evil is a self-centered ignorance that leads to harmful actions. If I am correct about that definition of evil, then an all-evil god is impossible. The challenge certainly does nothing to refute the god hypothesis.