Scenario 1) Doom most likely.<br/><br/>Scenario 2) Batman maybe? If going by what he could bring and has access to. Like maybe the phantom zone piece that Superman has stored around. That's if they can transport it. Otherwise, Doom has great favor as well.<br/><br/>Scenario 3) is kinda tough. Especially since Batman has access to the Watchtower's giant beam of death that could literally incinerate Dr. Doom.<br/><br/><br/>All in all, I honestly don't know enough about Doom to beat him.